intigrate others sales , return and implement day end duntinalities

Backend/ERPCore/Controllers/SalesDayEndController.cs

@@ -0,0 +1,50 @@
+using ERPCore.Dtos.Common;
+using ERPCore.Dtos.Sales;
+using ERPCore.Services.Interfaces;
+using Microsoft.AspNetCore.Mvc;
+
+namespace ERPCore.Controllers;
+
+/// <summary>Cashier day-end close-out — locks a cashier's Posted sales slips for a business
+/// date and posts one consolidated GL journal entry for the day (docs/14 Sales API).</summary>
+[Route("api/v1/sales-day-end")]
+public sealed class SalesDayEndController : ApiControllerBase
+{
+    private readonly ISalesDayEndService _dayEnds;
+
+    public SalesDayEndController(ISalesDayEndService dayEnds) => _dayEnds = dayEnds;
+
+    /// <summary>List day-end closes, newest first.</summary>
+    [HttpGet]
+    [ProducesResponseType(typeof(PagedResponse<SalesDayEndSummaryDto>), StatusCodes.Status200OK)]
+    public async Task<ActionResult<PagedResponse<SalesDayEndSummaryDto>>> List(
+        [FromQuery] PageQuery query, [FromQuery] int? cashierUserId, CancellationToken ct)
+        => Ok(await _dayEnds.ListAsync(query, cashierUserId, ct));
+
+    /// <summary>What closing this cashier/date right now would include (or the existing close's totals, if already closed).</summary>
+    [HttpGet("preview")]
+    [ProducesResponseType(typeof(SalesDayEndPreviewDto), StatusCodes.Status200OK)]
+    public async Task<ActionResult<SalesDayEndPreviewDto>> Preview(
+        [FromQuery] int cashierUserId, [FromQuery] DateOnly? businessDate, CancellationToken ct)
+        => Ok(await _dayEnds.PreviewAsync(cashierUserId, businessDate ?? DateOnly.FromDateTime(DateTime.UtcNow), ct));
+
+    [HttpGet("{salesDayEndId:int}")]
+    [ProducesResponseType(typeof(SalesDayEndDto), StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status404NotFound)]
+    public async Task<ActionResult<SalesDayEndDto>> GetById(int salesDayEndId, CancellationToken ct)
+    {
+        var dto = await _dayEnds.GetAsync(salesDayEndId, ct);
+        return dto is null ? NotFound() : Ok(dto);
+    }
+
+    /// <summary>Close the day: lock every Posted slip for (CashierUserId, BusinessDate) and post the
+    /// consolidated GL journal entry. Idempotent — closing an already-closed date replays it.</summary>
+    [HttpPost]
+    [ProducesResponseType(typeof(SalesDayEndDto), StatusCodes.Status201Created)]
+    [ProducesResponseType(StatusCodes.Status409Conflict)]
+    public async Task<ActionResult<SalesDayEndDto>> Close([FromBody] CreateSalesDayEndRequest request, CancellationToken ct)
+    {
+        var dto = await _dayEnds.CloseAsync(request, ct);
+        return Created($"/api/v1/sales-day-end/{dto.SalesDayEndId}", dto);
+    }
+}

Backend/ERPCore/Controllers/SalesInvoicesController.cs

@@ -10,8 +10,13 @@ namespace ERPCore.Controllers;
 public sealed class SalesInvoicesController : ApiControllerBase
 {
     private readonly ISalesInvoiceService _invoices;
+    private readonly ISalesInvoicePaymentService _payments;
 
-    public SalesInvoicesController(ISalesInvoiceService invoices) => _invoices = invoices;
+    public SalesInvoicesController(ISalesInvoiceService invoices, ISalesInvoicePaymentService payments)
+    {
+        _invoices = invoices;
+        _payments = payments;
+    }
 
     [HttpGet]
     [ProducesResponseType(typeof(PagedResponse<SalesInvoiceSummaryDto>), StatusCodes.Status200OK)]
@@ -70,4 +75,23 @@ public sealed class SalesInvoicesController : ApiControllerBase
     [ProducesResponseType(typeof(SalesInvoiceDto), StatusCodes.Status200OK)]
     public async Task<ActionResult<SalesInvoiceDto>> Cancel(int salesInvoiceId, CancellationToken ct)
         => Ok(await _invoices.CancelAsync(salesInvoiceId, ct));
+
+    /// <summary>Pay the customer's balance against this invoice, in full or in installments; posts a real GL journal entry.</summary>
+    [HttpPost("{salesInvoiceId:int}/payments")]
+    [ProducesResponseType(typeof(SalesInvoicePaymentDto), StatusCodes.Status201Created)]
+    [ProducesResponseType(StatusCodes.Status400BadRequest)]
+    [ProducesResponseType(StatusCodes.Status404NotFound)]
+    [ProducesResponseType(StatusCodes.Status409Conflict)]
+    public async Task<ActionResult<SalesInvoicePaymentDto>> Pay(int salesInvoiceId, [FromBody] CreateSalesInvoicePaymentRequest request, CancellationToken ct)
+    {
+        var dto = await _payments.PayAsync(salesInvoiceId, request, ct);
+        return Created($"/api/v1/sales-invoices/{salesInvoiceId}/payments/{dto.SalesInvoicePaymentId}", dto);
+    }
+
+    /// <summary>Payment history for this invoice, newest first.</summary>
+    [HttpGet("{salesInvoiceId:int}/payments")]
+    [ProducesResponseType(typeof(IReadOnlyList<SalesInvoicePaymentDto>), StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status404NotFound)]
+    public async Task<ActionResult<IReadOnlyList<SalesInvoicePaymentDto>>> ListPayments(int salesInvoiceId, CancellationToken ct)
+        => Ok(await _payments.ListAsync(salesInvoiceId, ct));
 }

Backend/ERPCore/Domain/DocumentTypes.cs

@@ -21,4 +21,7 @@ public static class DocumentTypes
     public const string SalesSlip = "SSL";
     public const string BundleSale = "BND";
     public const string SalesReturn = "SRET";
+
+    /// <summary>Cashier day-end close-out (Sales) — <c>DEND-2026-00001</c>.</summary>
+    public const string SalesDayEnd = "DEND";
 }

Backend/ERPCore/Domain/Entities/BundleSale.cs

@@ -29,5 +29,11 @@ public class BundleSale
     public DateTime? UpdatedAt { get; set; }
     public int ConcurrencyStamp { get; set; }
 
+    /// <summary>Set once this bundle's business date is closed by <see cref="SalesDayEnd"/> — a
+    /// closed bundle sale is frozen (no further edits). Same role as <see cref="SalesSlip.DayEndId"/>;
+    /// a bundle sale is a cashier document exactly like a sales slip, just priced as a set.</summary>
+    public int? DayEndId { get; set; }
+    public SalesDayEnd? DayEnd { get; set; }
+
     public ICollection<BundleSaleLine> Lines { get; set; } = new List<BundleSaleLine>();
 }

Backend/ERPCore/Domain/Entities/PurchaseReturn.cs

@@ -28,5 +28,12 @@ public class PurchaseReturn
 
     public DateTime CreatedAt { get; set; }
 
+    /// <summary>Journal number of the real GL journal entry posted for this return (set on create — it auto-posts).
+    /// Reverses the Inventory/Clearing lines a Grn posts — <see cref="PurchaseReturnLine"/> carries no unit
+    /// price/VAT of its own, so it can't reverse a VAT-recoverable line the way a real credit note would.</summary>
+    public string? GlJournalNo { get; set; }
+    public DateTime? GlPostedAt { get; set; }
+
     public ICollection<PurchaseReturnLine> Lines { get; set; } = new List<PurchaseReturnLine>();
 }
+

Backend/ERPCore/Domain/Entities/SalesDayEnd.cs

@@ -0,0 +1,46 @@
+namespace ERPCore.Domain.Entities;
+
+/// <summary>
+/// A cashier's end-of-day close-out. Aggregates every <see cref="SalesSlip"/> the
+/// cashier posted on <see cref="BusinessDate"/>, freezes them against this record
+/// (<see cref="SalesSlip.DayEndId"/>) so a slip can only ever belong to one day-end,
+/// and posts one consolidated GL journal entry for the day's revenue/tax/COGS —
+/// the sales-side equivalent of how <see cref="Grn"/> posts per receipt. Unique per
+/// (CashierUserId, BusinessDate): closing twice replays the existing record instead
+/// of creating a second one (same idempotent-replay pattern as Grn.ConfirmAsync).
+/// </summary>
+public class SalesDayEnd
+{
+    public int SalesDayEndId { get; set; }
+    public string DocNo { get; set; } = string.Empty;
+
+    public int CashierUserId { get; set; }
+    public User? CashierUser { get; set; }
+
+    /// <summary>The calendar date being closed (matched against each slip's <see cref="SalesSlip.SlipDate"/>, UTC).</summary>
+    public DateOnly BusinessDate { get; set; }
+
+    public int SlipCount { get; set; }
+    public int BundleCount { get; set; }
+    public decimal Subtotal { get; set; }
+    public decimal DiscountTotal { get; set; }
+    public decimal TaxTotal { get; set; }
+    public decimal GrandTotal { get; set; }
+
+    /// <summary>Sum of the FIFO cost consumed for these slips (from <see cref="StockLedger"/>), for the COGS GL lines.</summary>
+    public decimal CostOfGoodsSold { get; set; }
+
+    /// <summary>Journal number of the real GL journal entry posted for this close (null when there was nothing to post).</summary>
+    public string? GlJournalNo { get; set; }
+    public DateTime? GlPostedAt { get; set; }
+
+    public int ClosedBy { get; set; }
+    public User? ClosedByUser { get; set; }
+    public DateTime ClosedAt { get; set; }
+
+    /// <summary>PostgreSQL xmin-backed optimistic concurrency token.</summary>
+    public uint RowVersion { get; set; }
+
+    public ICollection<SalesSlip> Slips { get; set; } = new List<SalesSlip>();
+    public ICollection<BundleSale> BundleSales { get; set; } = new List<BundleSale>();
+}

Backend/ERPCore/Domain/Entities/SalesInvoice.cs

@@ -29,6 +29,14 @@ public class SalesInvoice
     public decimal PaidAmount { get; set; }
     public decimal BalanceAmount { get; set; }
 
+    /// <summary>Journal number of the revenue-recognition GL journal entry posted when this
+    /// invoice is Posted (Debit Accounts Receivable / Credit Sales Revenue + Tax, plus COGS —
+    /// see SalesPostingService.PostInvoiceAsync). Unlike a SalesSlip, an invoice posts its own
+    /// GL entry immediately rather than waiting for Sales Day End, since invoices aren't a
+    /// cashier document and don't go through that close-out.</summary>
+    public string? GlJournalNo { get; set; }
+    public DateTime? GlPostedAt { get; set; }
+
     public int CreatedBy { get; set; }
     public User? Creator { get; set; }
 
@@ -38,4 +46,5 @@ public class SalesInvoice
     public uint RowVersion { get; set; }
 
     public ICollection<SalesInvoiceLine> Lines { get; set; } = new List<SalesInvoiceLine>();
+    public ICollection<SalesInvoicePayment> Payments { get; set; } = new List<SalesInvoicePayment>();
 }

Backend/ERPCore/Domain/Entities/SalesInvoicePayment.cs

@@ -0,0 +1,32 @@
+namespace ERPCore.Domain.Entities;
+
+/// <summary>
+/// A customer payment made against a Posted sales invoice's balance (installments
+/// allowed — see SalesInvoicePaymentService.PayAsync). Posts its own real GL journal
+/// entry (Debit the selected bank-or-cash account / Credit Accounts Receivable) before
+/// being recorded here — the mirror image of <see cref="GrnPayment"/>.
+/// </summary>
+public class SalesInvoicePayment
+{
+    public int SalesInvoicePaymentId { get; set; }
+
+    public int SalesInvoiceId { get; set; }
+    public SalesInvoice? SalesInvoice { get; set; }
+
+    public decimal Amount { get; set; }
+    public DateTime PaymentDate { get; set; }
+
+    /// <summary>GL's numeric id for the bank/cash account the payment was received into.</summary>
+    public long GlBankAccountId { get; set; }
+    /// <summary>Snapshot of the account's display name at payment time (GL account lists have no local FK).</summary>
+    public string BankAccountName { get; set; } = string.Empty;
+
+    public string? Reference { get; set; }
+
+    /// <summary>Journal number of the real GL journal entry this payment posted.</summary>
+    public string? GlJournalNo { get; set; }
+
+    public int CreatedBy { get; set; }
+    public User? Creator { get; set; }
+    public DateTime CreatedAt { get; set; }
+}

Backend/ERPCore/Domain/Entities/SalesReturn.cs

@@ -28,5 +28,11 @@ public class SalesReturn
 
     public DateTime CreatedAt { get; set; }
 
+    /// <summary>Journal number of the real GL journal entry posted for this return (set on create — it auto-posts).
+    /// Reverses Inventory/COGS only — <see cref="SalesReturnLine"/> carries no unit price, so revenue/tax aren't
+    /// reversed here (they'd need a per-line price this document doesn't capture).</summary>
+    public string? GlJournalNo { get; set; }
+    public DateTime? GlPostedAt { get; set; }
+
     public ICollection<SalesReturnLine> Lines { get; set; } = new List<SalesReturnLine>();
 }

Backend/ERPCore/Domain/Entities/SalesSlip.cs

@@ -27,6 +27,10 @@ public class SalesSlip
     public decimal PaidAmount { get; set; }
     public decimal BalanceAmount { get; set; }
 
+    /// <summary>Set once this slip's business date is closed by <see cref="SalesDayEnd"/> — a closed slip is frozen (no further edits).</summary>
+    public int? DayEndId { get; set; }
+    public SalesDayEnd? DayEnd { get; set; }
+
     public DateTime CreatedAt { get; set; }
     public DateTime? UpdatedAt { get; set; }
 

Backend/ERPCore/Domain/Entities/StockAdjustment.cs

@@ -27,5 +27,10 @@ public class StockAdjustment
     public DateTime CreatedAt { get; set; }
     public uint RowVersion { get; set; }
 
+    /// <summary>Journal number of the real GL journal entry posted for this adjustment (set on create — it
+    /// auto-posts). Increases and decreases post separately (never netted) so gains/losses stay visible.</summary>
+    public string? GlJournalNo { get; set; }
+    public DateTime? GlPostedAt { get; set; }
+
     public ICollection<StockAdjustmentLine> Lines { get; set; } = new List<StockAdjustmentLine>();
 }

Backend/ERPCore/Dtos/Procurement/PurchaseReturnDtos.cs

@@ -9,12 +9,13 @@ public sealed record PurchaseReturnLineDto(int ReturnLineId, int? GrnLineId, int
 
 public sealed record PurchaseReturnDto(
     int ReturnId, string DocNo, int VendorId, int WarehouseId, int ReasonCodeId, ReturnStatus Status,
-    int CreatedBy, DateTime CreatedAt, IReadOnlyList<PurchaseReturnLineDto> Lines, IReadOnlyList<int> LedgerRefs);
+    int CreatedBy, DateTime CreatedAt, string? GlJournalNo, DateTime? GlPostedAt,
+    IReadOnlyList<PurchaseReturnLineDto> Lines, IReadOnlyList<int> LedgerRefs);
 
 /// <summary>Row shape for <c>GET /purchase-returns</c> — no lines/ledgerRefs (those need a per-row query).</summary>
 public sealed record PurchaseReturnSummaryDto(
     int ReturnId, string DocNo, int VendorId, int WarehouseId, int ReasonCodeId, ReturnStatus Status,
-    int CreatedBy, DateTime CreatedAt, int LineCount);
+    int CreatedBy, DateTime CreatedAt, int LineCount, string? GlJournalNo);
 
 // Requests ----------------------------------------------------------------------
 

Backend/ERPCore/Dtos/Sales/SalesDayEndDtos.cs

@@ -0,0 +1,40 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace ERPCore.Dtos.Sales;
+
+// Responses -----------------------------------------------------------------------
+
+/// <summary>Qty/revenue sold for one item across a closed (or about-to-close) day, for the day-end report.
+/// Merges sales-slip and bundle-sale lines for the same item into one row.</summary>
+public sealed record SalesDayEndItemLineDto(int ItemId, string Sku, string Name, decimal Qty, decimal Revenue);
+
+public sealed record SalesDayEndDto(
+    int SalesDayEndId, string DocNo, int CashierUserId, DateOnly BusinessDate,
+    int SlipCount, int BundleCount, decimal Subtotal, decimal DiscountTotal, decimal TaxTotal, decimal GrandTotal,
+    decimal CostOfGoodsSold, string? GlJournalNo, DateTime? GlPostedAt, int ClosedBy, DateTime ClosedAt,
+    IReadOnlyList<string> SlipNumbers, IReadOnlyList<string> BundleNumbers, IReadOnlyList<SalesDayEndItemLineDto> ItemBreakdown);
+
+public sealed record SalesDayEndSummaryDto(
+    int SalesDayEndId, string DocNo, int CashierUserId, DateOnly BusinessDate,
+    int SlipCount, int BundleCount, decimal GrandTotal, string? GlJournalNo, DateTime ClosedAt);
+
+/// <summary>What closing right now would include — call before <c>POST /sales-day-end</c> so the
+/// cashier can see the day's totals, and any still-Draft slips/bundles blocking the close.</summary>
+public sealed record SalesDayEndPreviewDto(
+    int CashierUserId, DateOnly BusinessDate, bool AlreadyClosed,
+    int SlipCount, int BundleCount, decimal Subtotal, decimal DiscountTotal, decimal TaxTotal, decimal GrandTotal,
+    IReadOnlyList<string> SlipNumbers, IReadOnlyList<string> BundleNumbers,
+    IReadOnlyList<DraftSlipBlockingCloseDto> DraftSlipsBlockingClose,
+    IReadOnlyList<DraftBundleBlockingCloseDto> DraftBundleSalesBlockingClose);
+
+public sealed record DraftSlipBlockingCloseDto(int SalesSlipId, string SlipNo, decimal GrandTotal);
+public sealed record DraftBundleBlockingCloseDto(int BundleSaleId, string BundleNo, decimal GrandTotal);
+
+// Requests ------------------------------------------------------------------------
+
+public sealed class CreateSalesDayEndRequest
+{
+    [Required] public int CashierUserId { get; set; }
+    /// <summary>Defaults to today (UTC) when omitted.</summary>
+    public DateOnly? BusinessDate { get; set; }
+}

Backend/ERPCore/Dtos/Sales/SalesInvoiceDtos.cs

@@ -17,12 +17,24 @@ public sealed record SalesInvoiceDto(
     int SalesInvoiceId, string InvoiceNo, DateTime InvoiceDate, int CustomerId,
     string CustomerSnapshotName, string? CustomerSnapshotTaxNo, int WarehouseId,
     SalesInvoiceType InvoiceType, SalesInvoiceStatus Status, int CreatedBy, DateTime CreatedAt,
-    DateTime? UpdatedAt, SalesInvoiceTotalsDto Totals, IReadOnlyList<SalesInvoiceLineDto> Lines);
+    DateTime? UpdatedAt, string? GlJournalNo, DateTime? GlPostedAt,
+    SalesInvoiceTotalsDto Totals, IReadOnlyList<SalesInvoiceLineDto> Lines);
 
 public sealed record SalesInvoiceSummaryDto(
     int SalesInvoiceId, string InvoiceNo, DateTime InvoiceDate, int CustomerId,
     string CustomerSnapshotName, int WarehouseId, SalesInvoiceType InvoiceType,
-    SalesInvoiceStatus Status, SalesInvoiceTotalsDto Totals, DateTime CreatedAt);
+    SalesInvoiceStatus Status, SalesInvoiceTotalsDto Totals, DateTime CreatedAt, string? GlJournalNo);
+
+public sealed record SalesInvoicePaymentDto(
+    int SalesInvoicePaymentId, int SalesInvoiceId, decimal Amount, DateTime PaymentDate,
+    long GlBankAccountId, string BankAccountName, string? Reference, string? GlJournalNo, DateTime CreatedAt);
+
+public sealed class CreateSalesInvoicePaymentRequest
+{
+    [Range(0.01, double.MaxValue)] public decimal Amount { get; set; }
+    [Required] public long GlBankAccountId { get; set; }
+    [StringLength(100)] public string? Reference { get; set; }
+}
 
 public sealed record SalesInvoicePostingIssueDto(
     int SalesInvoiceLineId, int ItemId, string ItemSku, string ItemName, int WarehouseId,

Backend/ERPCore/Dtos/Sales/SalesReturnDtos.cs

@@ -9,12 +9,13 @@ public sealed record SalesReturnLineDto(int ReturnLineId, int? SalesInvoiceLineI
 
 public sealed record SalesReturnDto(
     int ReturnId, string DocNo, int CustomerId, int WarehouseId, int ReasonCodeId, ReturnStatus Status,
-    int CreatedBy, DateTime CreatedAt, IReadOnlyList<SalesReturnLineDto> Lines, IReadOnlyList<int> LedgerRefs);
+    int CreatedBy, DateTime CreatedAt, string? GlJournalNo, DateTime? GlPostedAt,
+    IReadOnlyList<SalesReturnLineDto> Lines, IReadOnlyList<int> LedgerRefs);
 
 /// <summary>Row shape for <c>GET /sales-returns</c> — no lines/ledgerRefs (those need a per-row query).</summary>
 public sealed record SalesReturnSummaryDto(
     int ReturnId, string DocNo, int CustomerId, int WarehouseId, int ReasonCodeId, ReturnStatus Status,
-    int CreatedBy, DateTime CreatedAt, int LineCount, decimal TotalQty);
+    int CreatedBy, DateTime CreatedAt, int LineCount, decimal TotalQty, string? GlJournalNo);
 
 /// <summary>
 /// Remaining returnable qty for one sales invoice line — the invoiced qty minus

Backend/ERPCore/Dtos/Stock/AdjustmentDtos.cs

@@ -9,12 +9,13 @@ public sealed record AdjustmentLineDto(int AdjLineId, int ItemId, int? BinId, in
 
 public sealed record AdjustmentDto(
     int AdjustmentId, string DocNo, int WarehouseId, int ReasonCodeId, AdjustmentStatus Status,
-    int CreatedBy, DateTime CreatedAt, IReadOnlyList<AdjustmentLineDto> Lines, IReadOnlyList<int> LedgerRefs);
+    int CreatedBy, DateTime CreatedAt, string? GlJournalNo, DateTime? GlPostedAt,
+    IReadOnlyList<AdjustmentLineDto> Lines, IReadOnlyList<int> LedgerRefs);
 
 /// <summary>Row shape for <c>GET /stock-adjustments</c> — no lines/ledgerRefs (those need a per-row query).</summary>
 public sealed record AdjustmentSummaryDto(
     int AdjustmentId, string DocNo, int WarehouseId, int ReasonCodeId, AdjustmentStatus Status,
-    int CreatedBy, DateTime CreatedAt, int LineCount);
+    int CreatedBy, DateTime CreatedAt, int LineCount, string? GlJournalNo);
 
 // Requests ----------------------------------------------------------------------
 

Backend/ERPCore/Dtos/Stock/CountDtos.cs

@@ -16,7 +16,7 @@ public sealed record CountSummaryDto(
     int CountId, string DocNo, int WarehouseId, CountType CountType, CountStatus Status,
     int CreatedBy, DateTime CreatedAt, int LineCount);
 
-public sealed record CountPostResultDto(int CountId, CountStatus Status, int? AdjustmentId, IReadOnlyList<int> LedgerRefs);
+public sealed record CountPostResultDto(int CountId, CountStatus Status, int? AdjustmentId, string? GlJournalNo, IReadOnlyList<int> LedgerRefs);
 
 // Requests ----------------------------------------------------------------------
 

Backend/ERPCore/Infra/Persistence/Configurations/PurchaseReturnConfiguration.cs

@@ -16,6 +16,7 @@ public sealed class PurchaseReturnConfiguration : IEntityTypeConfiguration<Purch
 
         builder.Property(r => r.Status).HasConversion<string>().HasMaxLength(20).IsRequired();
         builder.Property(r => r.CreatedAt).IsRequired();
+        builder.Property(r => r.GlJournalNo).HasMaxLength(30);
 
         builder.HasOne(r => r.Vendor).WithMany().HasForeignKey(r => r.VendorId).OnDelete(DeleteBehavior.Restrict);
         builder.HasOne(r => r.Warehouse).WithMany().HasForeignKey(r => r.WarehouseId).OnDelete(DeleteBehavior.Restrict);

Backend/ERPCore/Infra/Persistence/Configurations/SalesDayEndConfiguration.cs

@@ -0,0 +1,44 @@
+using ERPCore.Domain.Entities;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Metadata.Builders;
+
+namespace ERPCore.Infra.Persistence.Configurations;
+
+public sealed class SalesDayEndConfiguration : IEntityTypeConfiguration<SalesDayEnd>
+{
+    public void Configure(EntityTypeBuilder<SalesDayEnd> builder)
+    {
+        builder.ToTable("sales_day_ends");
+        builder.HasKey(x => x.SalesDayEndId);
+
+        builder.Property(x => x.DocNo).IsRequired().HasMaxLength(30);
+        builder.HasIndex(x => x.DocNo).IsUnique();
+
+        builder.Property(x => x.BusinessDate).IsRequired();
+
+        foreach (var p in new[] { nameof(SalesDayEnd.Subtotal), nameof(SalesDayEnd.DiscountTotal), nameof(SalesDayEnd.TaxTotal), nameof(SalesDayEnd.GrandTotal), nameof(SalesDayEnd.CostOfGoodsSold) })
+            builder.Property<decimal>(p).HasPrecision(18, 4);
+        builder.Property(x => x.BundleCount).HasDefaultValue(0);
+
+        builder.Property(x => x.GlJournalNo).HasMaxLength(30);
+        builder.Property(x => x.ClosedAt).IsRequired();
+        builder.Property(x => x.RowVersion).IsRowVersion();
+
+        builder.HasOne(x => x.CashierUser).WithMany().HasForeignKey(x => x.CashierUserId).OnDelete(DeleteBehavior.Restrict);
+        builder.HasOne(x => x.ClosedByUser).WithMany().HasForeignKey(x => x.ClosedBy).OnDelete(DeleteBehavior.Restrict);
+
+        // A cashier can only close a given business date once (CloseAsync replays this
+        // row idempotently on a second call instead of erroring — see SalesDayEndService).
+        builder.HasIndex(x => new { x.CashierUserId, x.BusinessDate }).IsUnique();
+
+        builder.HasMany(x => x.Slips)
+            .WithOne(x => x.DayEnd)
+            .HasForeignKey(x => x.DayEndId)
+            .OnDelete(DeleteBehavior.Restrict);
+
+        builder.HasMany(x => x.BundleSales)
+            .WithOne(x => x.DayEnd)
+            .HasForeignKey(x => x.DayEndId)
+            .OnDelete(DeleteBehavior.Restrict);
+    }
+}

Backend/ERPCore/Infra/Persistence/Configurations/SalesInvoiceConfiguration.cs

@@ -40,6 +40,7 @@ public sealed class SalesInvoiceConfiguration : IEntityTypeConfiguration<SalesIn
 
         foreach (var p in new[] { nameof(SalesInvoice.Subtotal), nameof(SalesInvoice.DiscountTotal), nameof(SalesInvoice.TaxTotal), nameof(SalesInvoice.GrandTotal), nameof(SalesInvoice.RoundOff), nameof(SalesInvoice.NetPayable), nameof(SalesInvoice.PaidAmount), nameof(SalesInvoice.BalanceAmount) })
             builder.Property<decimal>(p).HasPrecision(18, 4);
+        builder.Property(x => x.GlJournalNo).HasMaxLength(30);
 
         builder.Property(x => x.CreatedAt).IsRequired();
         builder.Property(x => x.RowVersion).IsRowVersion();
@@ -54,6 +55,27 @@ public sealed class SalesInvoiceConfiguration : IEntityTypeConfiguration<SalesIn
     }
 }
 
+public sealed class SalesInvoicePaymentConfiguration : IEntityTypeConfiguration<SalesInvoicePayment>
+{
+    public void Configure(EntityTypeBuilder<SalesInvoicePayment> builder)
+    {
+        builder.ToTable("sales_invoice_payments");
+        builder.HasKey(p => p.SalesInvoicePaymentId);
+
+        builder.Property(p => p.Amount).HasPrecision(18, 4);
+        builder.Property(p => p.PaymentDate).IsRequired();
+        builder.Property(p => p.BankAccountName).IsRequired().HasMaxLength(200);
+        builder.Property(p => p.Reference).HasMaxLength(100);
+        builder.Property(p => p.GlJournalNo).HasMaxLength(30);
+        builder.Property(p => p.CreatedAt).IsRequired();
+
+        builder.HasOne(p => p.SalesInvoice).WithMany(x => x.Payments).HasForeignKey(p => p.SalesInvoiceId).OnDelete(DeleteBehavior.Restrict);
+        builder.HasOne(p => p.Creator).WithMany().HasForeignKey(p => p.CreatedBy).OnDelete(DeleteBehavior.Restrict);
+
+        builder.HasIndex(p => p.SalesInvoiceId);
+    }
+}
+
 public sealed class SalesInvoiceLineConfiguration : IEntityTypeConfiguration<SalesInvoiceLine>
 {
     public void Configure(EntityTypeBuilder<SalesInvoiceLine> builder)

Backend/ERPCore/Infra/Persistence/Configurations/SalesReturnConfiguration.cs

@@ -16,6 +16,7 @@ public sealed class SalesReturnConfiguration : IEntityTypeConfiguration<SalesRet
 
         builder.Property(r => r.Status).HasConversion<string>().HasMaxLength(20).IsRequired();
         builder.Property(r => r.CreatedAt).IsRequired();
+        builder.Property(r => r.GlJournalNo).HasMaxLength(30);
 
         builder.HasOne(r => r.Customer).WithMany().HasForeignKey(r => r.CustomerId).OnDelete(DeleteBehavior.Restrict);
         builder.HasOne(r => r.Warehouse).WithMany().HasForeignKey(r => r.WarehouseId).OnDelete(DeleteBehavior.Restrict);

Backend/ERPCore/Infra/Persistence/Configurations/StockAdjustmentConfiguration.cs

@@ -16,6 +16,7 @@ public sealed class StockAdjustmentConfiguration : IEntityTypeConfiguration<Stoc
 
         builder.Property(a => a.Status).HasConversion<string>().HasMaxLength(20).IsRequired();
         builder.Property(a => a.CreatedAt).IsRequired();
+        builder.Property(a => a.GlJournalNo).HasMaxLength(30);
         builder.Property(a => a.RowVersion).IsRowVersion();
 
         builder.HasOne(a => a.Warehouse).WithMany().HasForeignKey(a => a.WarehouseId).OnDelete(DeleteBehavior.Restrict);

Backend/ERPCore/Infra/Persistence/ErpDbContext.cs

@@ -88,8 +88,10 @@ public class ErpDbContext : DbContext
     // --- Sales (Phase 1) ---
     public DbSet<SalesInvoice> SalesInvoices => Set<SalesInvoice>();
     public DbSet<SalesInvoiceLine> SalesInvoiceLines => Set<SalesInvoiceLine>();
+    public DbSet<SalesInvoicePayment> SalesInvoicePayments => Set<SalesInvoicePayment>();
     public DbSet<SalesSlip> SalesSlips => Set<SalesSlip>();
     public DbSet<SalesSlipLine> SalesSlipLines => Set<SalesSlipLine>();
+    public DbSet<SalesDayEnd> SalesDayEnds => Set<SalesDayEnd>();
     public DbSet<BundleSaleTemplate> BundleSaleTemplates => Set<BundleSaleTemplate>();
     public DbSet<BundleSaleTemplateLine> BundleSaleTemplateLines => Set<BundleSaleTemplateLine>();
     public DbSet<BundleSale> BundleSales => Set<BundleSale>();

Backend/ERPCore/Migrations/20260816130723_AddSalesDayEnd.cs

@@ -0,0 +1,109 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace ERPCore.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddSalesDayEnd : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<int>(
+                name: "DayEndId",
+                table: "sales_slips",
+                type: "integer",
+                nullable: true);
+
+            migrationBuilder.CreateTable(
+                name: "sales_day_ends",
+                columns: table => new
+                {
+                    SalesDayEndId = table.Column<int>(type: "integer", nullable: false)
+                        .Annotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.IdentityByDefaultColumn),
+                    DocNo = table.Column<string>(type: "character varying(30)", maxLength: 30, nullable: false),
+                    CashierUserId = table.Column<int>(type: "integer", nullable: false),
+                    BusinessDate = table.Column<DateOnly>(type: "date", nullable: false),
+                    SlipCount = table.Column<int>(type: "integer", nullable: false),
+                    Subtotal = table.Column<decimal>(type: "numeric(18,4)", precision: 18, scale: 4, nullable: false),
+                    DiscountTotal = table.Column<decimal>(type: "numeric(18,4)", precision: 18, scale: 4, nullable: false),
+                    TaxTotal = table.Column<decimal>(type: "numeric(18,4)", precision: 18, scale: 4, nullable: false),
+                    GrandTotal = table.Column<decimal>(type: "numeric(18,4)", precision: 18, scale: 4, nullable: false),
+                    CostOfGoodsSold = table.Column<decimal>(type: "numeric(18,4)", precision: 18, scale: 4, nullable: false),
+                    GlJournalNo = table.Column<string>(type: "character varying(30)", maxLength: 30, nullable: true),
+                    GlPostedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: true),
+                    ClosedBy = table.Column<int>(type: "integer", nullable: false),
+                    ClosedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: false),
+                    xmin = table.Column<uint>(type: "xid", rowVersion: true, nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_sales_day_ends", x => x.SalesDayEndId);
+                    table.ForeignKey(
+                        name: "FK_sales_day_ends_users_CashierUserId",
+                        column: x => x.CashierUserId,
+                        principalTable: "users",
+                        principalColumn: "UserId",
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "FK_sales_day_ends_users_ClosedBy",
+                        column: x => x.ClosedBy,
+                        principalTable: "users",
+                        principalColumn: "UserId",
+                        onDelete: ReferentialAction.Restrict);
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_sales_slips_DayEndId",
+                table: "sales_slips",
+                column: "DayEndId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_sales_day_ends_CashierUserId_BusinessDate",
+                table: "sales_day_ends",
+                columns: new[] { "CashierUserId", "BusinessDate" },
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "IX_sales_day_ends_ClosedBy",
+                table: "sales_day_ends",
+                column: "ClosedBy");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_sales_day_ends_DocNo",
+                table: "sales_day_ends",
+                column: "DocNo",
+                unique: true);
+
+            migrationBuilder.AddForeignKey(
+                name: "FK_sales_slips_sales_day_ends_DayEndId",
+                table: "sales_slips",
+                column: "DayEndId",
+                principalTable: "sales_day_ends",
+                principalColumn: "SalesDayEndId",
+                onDelete: ReferentialAction.Restrict);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropForeignKey(
+                name: "FK_sales_slips_sales_day_ends_DayEndId",
+                table: "sales_slips");
+
+            migrationBuilder.DropTable(
+                name: "sales_day_ends");
+
+            migrationBuilder.DropIndex(
+                name: "IX_sales_slips_DayEndId",
+                table: "sales_slips");
+
+            migrationBuilder.DropColumn(
+                name: "DayEndId",
+                table: "sales_slips");
+        }
+    }
+}

Backend/ERPCore/Migrations/20260816133305_AddReturnGlPosting.cs

@@ -0,0 +1,61 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ERPCore.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddReturnGlPosting : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<string>(
+                name: "GlJournalNo",
+                table: "sales_returns",
+                type: "character varying(30)",
+                maxLength: 30,
+                nullable: true);
+
+            migrationBuilder.AddColumn<DateTime>(
+                name: "GlPostedAt",
+                table: "sales_returns",
+                type: "timestamp with time zone",
+                nullable: true);
+
+            migrationBuilder.AddColumn<string>(
+                name: "GlJournalNo",
+                table: "purchase_returns",
+                type: "character varying(30)",
+                maxLength: 30,
+                nullable: true);
+
+            migrationBuilder.AddColumn<DateTime>(
+                name: "GlPostedAt",
+                table: "purchase_returns",
+                type: "timestamp with time zone",
+                nullable: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "GlJournalNo",
+                table: "sales_returns");
+
+            migrationBuilder.DropColumn(
+                name: "GlPostedAt",
+                table: "sales_returns");
+
+            migrationBuilder.DropColumn(
+                name: "GlJournalNo",
+                table: "purchase_returns");
+
+            migrationBuilder.DropColumn(
+                name: "GlPostedAt",
+                table: "purchase_returns");
+        }
+    }
+}

Backend/ERPCore/Migrations/20260816142234_AddAdjustmentGlPosting.cs

@@ -0,0 +1,40 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ERPCore.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddAdjustmentGlPosting : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<string>(
+                name: "GlJournalNo",
+                table: "stock_adjustments",
+                type: "character varying(30)",
+                maxLength: 30,
+                nullable: true);
+
+            migrationBuilder.AddColumn<DateTime>(
+                name: "GlPostedAt",
+                table: "stock_adjustments",
+                type: "timestamp with time zone",
+                nullable: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "GlJournalNo",
+                table: "stock_adjustments");
+
+            migrationBuilder.DropColumn(
+                name: "GlPostedAt",
+                table: "stock_adjustments");
+        }
+    }
+}

Backend/ERPCore/Migrations/20260816151344_AddBundleSaleToDayEnd.cs

@@ -0,0 +1,60 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ERPCore.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddBundleSaleToDayEnd : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<int>(
+                name: "BundleCount",
+                table: "sales_day_ends",
+                type: "integer",
+                nullable: false,
+                defaultValue: 0);
+
+            migrationBuilder.AddColumn<int>(
+                name: "DayEndId",
+                table: "bundle_sales",
+                type: "integer",
+                nullable: true);
+
+            migrationBuilder.CreateIndex(
+                name: "IX_bundle_sales_DayEndId",
+                table: "bundle_sales",
+                column: "DayEndId");
+
+            migrationBuilder.AddForeignKey(
+                name: "FK_bundle_sales_sales_day_ends_DayEndId",
+                table: "bundle_sales",
+                column: "DayEndId",
+                principalTable: "sales_day_ends",
+                principalColumn: "SalesDayEndId",
+                onDelete: ReferentialAction.Restrict);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropForeignKey(
+                name: "FK_bundle_sales_sales_day_ends_DayEndId",
+                table: "bundle_sales");
+
+            migrationBuilder.DropIndex(
+                name: "IX_bundle_sales_DayEndId",
+                table: "bundle_sales");
+
+            migrationBuilder.DropColumn(
+                name: "BundleCount",
+                table: "sales_day_ends");
+
+            migrationBuilder.DropColumn(
+                name: "DayEndId",
+                table: "bundle_sales");
+        }
+    }
+}

Backend/ERPCore/Migrations/20260816174034_AddSalesInvoicePayments.cs

@@ -0,0 +1,87 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace ERPCore.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddSalesInvoicePayments : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<string>(
+                name: "GlJournalNo",
+                table: "sales_invoices",
+                type: "character varying(30)",
+                maxLength: 30,
+                nullable: true);
+
+            migrationBuilder.AddColumn<DateTime>(
+                name: "GlPostedAt",
+                table: "sales_invoices",
+                type: "timestamp with time zone",
+                nullable: true);
+
+            migrationBuilder.CreateTable(
+                name: "sales_invoice_payments",
+                columns: table => new
+                {
+                    SalesInvoicePaymentId = table.Column<int>(type: "integer", nullable: false)
+                        .Annotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.IdentityByDefaultColumn),
+                    SalesInvoiceId = table.Column<int>(type: "integer", nullable: false),
+                    Amount = table.Column<decimal>(type: "numeric(18,4)", precision: 18, scale: 4, nullable: false),
+                    PaymentDate = table.Column<DateTime>(type: "timestamp with time zone", nullable: false),
+                    GlBankAccountId = table.Column<long>(type: "bigint", nullable: false),
+                    BankAccountName = table.Column<string>(type: "character varying(200)", maxLength: 200, nullable: false),
+                    Reference = table.Column<string>(type: "character varying(100)", maxLength: 100, nullable: true),
+                    GlJournalNo = table.Column<string>(type: "character varying(30)", maxLength: 30, nullable: true),
+                    CreatedBy = table.Column<int>(type: "integer", nullable: false),
+                    CreatedAt = table.Column<DateTime>(type: "timestamp with time zone", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_sales_invoice_payments", x => x.SalesInvoicePaymentId);
+                    table.ForeignKey(
+                        name: "FK_sales_invoice_payments_sales_invoices_SalesInvoiceId",
+                        column: x => x.SalesInvoiceId,
+                        principalTable: "sales_invoices",
+                        principalColumn: "SalesInvoiceId",
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "FK_sales_invoice_payments_users_CreatedBy",
+                        column: x => x.CreatedBy,
+                        principalTable: "users",
+                        principalColumn: "UserId",
+                        onDelete: ReferentialAction.Restrict);
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_sales_invoice_payments_CreatedBy",
+                table: "sales_invoice_payments",
+                column: "CreatedBy");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_sales_invoice_payments_SalesInvoiceId",
+                table: "sales_invoice_payments",
+                column: "SalesInvoiceId");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "sales_invoice_payments");
+
+            migrationBuilder.DropColumn(
+                name: "GlJournalNo",
+                table: "sales_invoices");
+
+            migrationBuilder.DropColumn(
+                name: "GlPostedAt",
+                table: "sales_invoices");
+        }
+    }
+}

Backend/ERPCore/Migrations/ErpDbContextModelSnapshot.cs

@@ -422,6 +422,9 @@ namespace ERPCore.Migrations
                         .HasMaxLength(200)
                         .HasColumnType("character varying(200)");
 
+                    b.Property<int?>("DayEndId")
+                        .HasColumnType("integer");
+
                     b.Property<decimal>("DiscountTotal")
                         .HasPrecision(18, 4)
                         .HasColumnType("numeric(18,4)");
@@ -462,6 +465,8 @@ namespace ERPCore.Migrations
 
                     b.HasIndex("CustomerId");
 
+                    b.HasIndex("DayEndId");
+
                     b.HasIndex("WarehouseId");
 
                     b.ToTable("bundle_sales", (string)null);
@@ -1552,6 +1557,33 @@ namespace ERPCore.Migrations
                     b.ToTable("grn_lines", (string)null);
                 });
 
+            modelBuilder.Entity("ERPCore.Domain.Entities.GrnLineWarrantyNumber", b =>
+                {
+                    b.Property<int>("GrnLineWarrantyNumberId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("GrnLineWarrantyNumberId"));
+
+                    b.Property<int>("GrnLineId")
+                        .HasColumnType("integer");
+
+                    b.Property<string>("WarrantyNo")
+                        .IsRequired()
+                        .HasMaxLength(100)
+                        .HasColumnType("character varying(100)");
+
+                    b.Property<int>("WarrantyPeriodMonths")
+                        .HasColumnType("integer");
+
+                    b.HasKey("GrnLineWarrantyNumberId");
+
+                    b.HasIndex("GrnLineId", "WarrantyNo")
+                        .IsUnique();
+
+                    b.ToTable("grn_line_warranty_numbers", (string)null);
+                });
+
             modelBuilder.Entity("ERPCore.Domain.Entities.GrnPayment", b =>
                 {
                     b.Property<int>("GrnPaymentId")
@@ -1601,33 +1633,6 @@ namespace ERPCore.Migrations
                     b.ToTable("grn_payments", (string)null);
                 });
 
-            modelBuilder.Entity("ERPCore.Domain.Entities.GrnLineWarrantyNumber", b =>
-                {
-                    b.Property<int>("GrnLineWarrantyNumberId")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("integer");
-
-                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("GrnLineWarrantyNumberId"));
-
-                    b.Property<int>("GrnLineId")
-                        .HasColumnType("integer");
-
-                    b.Property<string>("WarrantyNo")
-                        .IsRequired()
-                        .HasMaxLength(100)
-                        .HasColumnType("character varying(100)");
-
-                    b.Property<int>("WarrantyPeriodMonths")
-                        .HasColumnType("integer");
-
-                    b.HasKey("GrnLineWarrantyNumberId");
-
-                    b.HasIndex("GrnLineId", "WarrantyNo")
-                        .IsUnique();
-
-                    b.ToTable("grn_line_warranty_numbers", (string)null);
-                });
-
             modelBuilder.Entity("ERPCore.Domain.Entities.HrDocumentType", b =>
                 {
                     b.Property<int>("HrDocumentTypeId")
@@ -3171,6 +3176,13 @@ namespace ERPCore.Migrations
                         .HasMaxLength(30)
                         .HasColumnType("character varying(30)");
 
+                    b.Property<string>("GlJournalNo")
+                        .HasMaxLength(30)
+                        .HasColumnType("character varying(30)");
+
+                    b.Property<DateTime?>("GlPostedAt")
+                        .HasColumnType("timestamp with time zone");
+
                     b.Property<int>("ReasonCodeId")
                         .HasColumnType("integer");
 
@@ -3776,6 +3788,85 @@ namespace ERPCore.Migrations
                     b.ToTable("hr_salary_components", (string)null);
                 });
 
+            modelBuilder.Entity("ERPCore.Domain.Entities.SalesDayEnd", b =>
+                {
+                    b.Property<int>("SalesDayEndId")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("SalesDayEndId"));
+
+                    b.Property<int>("BundleCount")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("integer")
+                        .HasDefaultValue(0);
+
+                    b.Property<DateOnly>("BusinessDate")
+                        .HasColumnType("date");
+
+                    b.Property<int>("CashierUserId")
+                        .HasColumnType("integer");
+
+                    b.Property<DateTime>("ClosedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<int>("ClosedBy")
+                        .HasColumnType("integer");
+
+                    b.Property<decimal>("CostOfGoodsSold")
+                        .HasPrecision(18, 4)
+                        .HasColumnType("numeric(18,4)");
+
+                    b.Property<decimal>("DiscountTotal")
+                        .HasPrecision(18, 4)
+                        .HasColumnType("numeric(18,4)");
+
+                    b.Property<string>("DocNo")
+                        .IsRequired()
+                        .HasMaxLength(30)
+                        .HasColumnType("character varying(30)");
+
+                    b.Property<string>("GlJournalNo")
+                        .HasMaxLength(30)
+                        .HasColumnType("character varying(30)");
+
+                    b.Property<DateTime?>("GlPostedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<decimal>("GrandTotal")
+                        .HasPrecision(18, 4)
+                        .HasColumnType("numeric(18,4)");
+
+                    b.Property<uint>("RowVersion")
+                        .IsConcurrencyToken()
+                        .ValueGeneratedOnAddOrUpdate()
+                        .HasColumnType("xid")
+                        .HasColumnName("xmin");
+
+                    b.Property<int>("SlipCount")
+                        .HasColumnType("integer");
+
+                    b.Property<decimal>("Subtotal")
+                        .HasPrecision(18, 4)
+                        .HasColumnType("numeric(18,4)");
+
+                    b.Property<decimal>("TaxTotal")
+                        .HasPrecision(18, 4)
+                        .HasColumnType("numeric(18,4)");
+
+                    b.HasKey("SalesDayEndId");
+
+                    b.HasIndex("ClosedBy");
+
+                    b.HasIndex("DocNo")
+                        .IsUnique();
+
+                    b.HasIndex("CashierUserId", "BusinessDate")
+                        .IsUnique();
+
+                    b.ToTable("sales_day_ends", (string)null);
+                });
+
             modelBuilder.Entity("ERPCore.Domain.Entities.SalesInvoice", b =>
                 {
                     b.Property<int>("SalesInvoiceId")
@@ -3813,6 +3904,13 @@ namespace ERPCore.Migrations
                         .HasPrecision(18, 4)
                         .HasColumnType("numeric(18,4)");
 
+                    b.Property<string>("GlJournalNo")
+                        .HasMaxLength(30)
+                        .HasColumnType("character varying(30)");
+
+                    b.Property<DateTime?>("GlPostedAt")
+                        .HasColumnType("timestamp with time zone");
+
                     b.Property<decimal>("GrandTotal")
                         .HasPrecision(18, 4)
                         .HasColumnType("numeric(18,4)");
@@ -3982,85 +4080,53 @@ namespace ERPCore.Migrations
                     b.ToTable("sales_invoice_lines", (string)null);
                 });
 
-            modelBuilder.Entity("ERPCore.Domain.Entities.SalesReturn", b =>
+            modelBuilder.Entity("ERPCore.Domain.Entities.SalesInvoicePayment", b =>
                 {
-                    b.Property<int>("ReturnId")
+                    b.Property<int>("SalesInvoicePaymentId")
                         .ValueGeneratedOnAdd()
                         .HasColumnType("integer");
 
-                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("ReturnId"));
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("SalesInvoicePaymentId"));
 
-                    b.Property<DateTime>("CreatedAt")
-                        .HasColumnType("timestamp with time zone");
-
-                    b.Property<int>("CreatedBy")
-                        .HasColumnType("integer");
-
-                    b.Property<int>("CustomerId")
-                        .HasColumnType("integer");
-
-                    b.Property<string>("DocNo")
-                        .IsRequired()
-                        .HasMaxLength(30)
-                        .HasColumnType("character varying(30)");
-
-                    b.Property<int>("ReasonCodeId")
-                        .HasColumnType("integer");
-
-                    b.Property<string>("Status")
-                        .IsRequired()
-                        .HasMaxLength(20)
-                        .HasColumnType("character varying(20)");
-
-                    b.Property<int>("WarehouseId")
-                        .HasColumnType("integer");
-
-                    b.HasKey("ReturnId");
-
-                    b.HasIndex("CreatedBy");
-
-                    b.HasIndex("CustomerId");
-
-                    b.HasIndex("DocNo")
-                        .IsUnique();
-
-                    b.HasIndex("ReasonCodeId");
-
-                    b.HasIndex("WarehouseId");
-
-                    b.ToTable("sales_returns", (string)null);
-                });
-
-            modelBuilder.Entity("ERPCore.Domain.Entities.SalesReturnLine", b =>
-                {
-                    b.Property<int>("ReturnLineId")
-                        .ValueGeneratedOnAdd()
-                        .HasColumnType("integer");
-
-                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<int>("ReturnLineId"));
-
-                    b.Property<int>("ItemId")
-                        .HasColumnType("integer");
-
-                    b.Property<decimal>("Qty")
+                    b.Property<decimal>("Amount")
                         .HasPrecision(18, 4)
                         .HasColumnType("numeric(18,4)");
 
-                    b.Property<int>("ReturnId")
+                    b.Property<string>("BankAccountName")
+                        .IsRequired()
+                        .HasMaxLength(200)
+                        .HasColumnType("character varying(200)");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<int>("CreatedBy")
                         .HasColumnType("integer");
 
-                    b.Property<int?>("SalesInvoiceLineId")
+                    b.Property<long>("GlBankAccountId")
+                        .HasColumnType("bigint");
+
+                    b.Property<string>("GlJournalNo")
+                        .HasMaxLength(30)
+                        .HasColumnType("character varying(30)");
+
+                    b.Property<DateTime>("PaymentDate")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("Reference")
+                        .HasMaxLength(100)
+                        .HasColumnType("character varying(100)");
+
+                    b.Property<int>("SalesInvoiceId")
                         .HasColumnType("integer");
 
-                    b.HasKey("ReturnLineId");
+                    b.HasKey("SalesInvoicePaymentId");
 
-                    b.HasIndex("ItemId");
+                    b.HasIndex("CreatedBy");
 
-                    b.HasIndex("ReturnId");
+                    b.HasIndex("SalesInvoiceId");
 
-                    b.HasIndex("SalesInvoiceLineId");
-
-                    b.ToTable("sales_return_lines", (string)null);
+                    b.ToTable("sales_invoice_payments", (string)null);
                 });
 
             modelBuilder.Entity("ERPCore.Domain.Entities.SalesReturn", b =>
@@ -4085,6 +4151,13 @@ namespace ERPCore.Migrations
                         .HasMaxLength(30)
                         .HasColumnType("character varying(30)");
 
+                    b.Property<string>("GlJournalNo")
+                        .HasMaxLength(30)
+                        .HasColumnType("character varying(30)");
+
+                    b.Property<DateTime?>("GlPostedAt")
+                        .HasColumnType("timestamp with time zone");
+
                     b.Property<int>("ReasonCodeId")
                         .HasColumnType("integer");
 
@@ -4170,6 +4243,9 @@ namespace ERPCore.Migrations
                         .HasMaxLength(200)
                         .HasColumnType("character varying(200)");
 
+                    b.Property<int?>("DayEndId")
+                        .HasColumnType("integer");
+
                     b.Property<decimal>("DiscountTotal")
                         .HasPrecision(18, 4)
                         .HasColumnType("numeric(18,4)");
@@ -4223,6 +4299,8 @@ namespace ERPCore.Migrations
 
                     b.HasIndex("CustomerId");
 
+                    b.HasIndex("DayEndId");
+
                     b.HasIndex("SlipDate");
 
                     b.HasIndex("SlipNo")
@@ -4484,6 +4562,13 @@ namespace ERPCore.Migrations
                         .HasMaxLength(30)
                         .HasColumnType("character varying(30)");
 
+                    b.Property<string>("GlJournalNo")
+                        .HasMaxLength(30)
+                        .HasColumnType("character varying(30)");
+
+                    b.Property<DateTime?>("GlPostedAt")
+                        .HasColumnType("timestamp with time zone");
+
                     b.Property<int>("ReasonCodeId")
                         .HasColumnType("integer");
 
@@ -5672,6 +5757,11 @@ namespace ERPCore.Migrations
                         .OnDelete(DeleteBehavior.Restrict)
                         .IsRequired();
 
+                    b.HasOne("ERPCore.Domain.Entities.SalesDayEnd", "DayEnd")
+                        .WithMany("BundleSales")
+                        .HasForeignKey("DayEndId")
+                        .OnDelete(DeleteBehavior.Restrict);
+
                     b.HasOne("ERPCore.Domain.Entities.Warehouse", "Warehouse")
                         .WithMany()
                         .HasForeignKey("WarehouseId")
@@ -5684,6 +5774,8 @@ namespace ERPCore.Migrations
 
                     b.Navigation("Customer");
 
+                    b.Navigation("DayEnd");
+
                     b.Navigation("Warehouse");
                 });
 
@@ -5976,6 +6068,17 @@ namespace ERPCore.Migrations
                     b.Navigation("PoLine");
                 });
 
+            modelBuilder.Entity("ERPCore.Domain.Entities.GrnLineWarrantyNumber", b =>
+                {
+                    b.HasOne("ERPCore.Domain.Entities.GrnLine", "GrnLine")
+                        .WithMany("WarrantyNumbers")
+                        .HasForeignKey("GrnLineId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("GrnLine");
+                });
+
             modelBuilder.Entity("ERPCore.Domain.Entities.GrnPayment", b =>
                 {
                     b.HasOne("ERPCore.Domain.Entities.User", "Creator")
@@ -5995,17 +6098,6 @@ namespace ERPCore.Migrations
                     b.Navigation("Grn");
                 });
 
-            modelBuilder.Entity("ERPCore.Domain.Entities.GrnLineWarrantyNumber", b =>
-                {
-                    b.HasOne("ERPCore.Domain.Entities.GrnLine", "GrnLine")
-                        .WithMany("WarrantyNumbers")
-                        .HasForeignKey("GrnLineId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.Navigation("GrnLine");
-                });
-
             modelBuilder.Entity("ERPCore.Domain.Entities.Item", b =>
                 {
                     b.HasOne("ERPCore.Domain.Entities.Uom", "BaseUom")
@@ -6579,6 +6671,25 @@ namespace ERPCore.Migrations
                     b.Navigation("Uom");
                 });
 
+            modelBuilder.Entity("ERPCore.Domain.Entities.SalesDayEnd", b =>
+                {
+                    b.HasOne("ERPCore.Domain.Entities.User", "CashierUser")
+                        .WithMany()
+                        .HasForeignKey("CashierUserId")
+                        .OnDelete(DeleteBehavior.Restrict)
+                        .IsRequired();
+
+                    b.HasOne("ERPCore.Domain.Entities.User", "ClosedByUser")
+                        .WithMany()
+                        .HasForeignKey("ClosedBy")
+                        .OnDelete(DeleteBehavior.Restrict)
+                        .IsRequired();
+
+                    b.Navigation("CashierUser");
+
+                    b.Navigation("ClosedByUser");
+                });
+
             modelBuilder.Entity("ERPCore.Domain.Entities.SalesInvoice", b =>
                 {
                     b.HasOne("ERPCore.Domain.Entities.User", "Creator")
@@ -6631,7 +6742,7 @@ namespace ERPCore.Migrations
                     b.Navigation("Warehouse");
                 });
 
-            modelBuilder.Entity("ERPCore.Domain.Entities.SalesReturn", b =>
+            modelBuilder.Entity("ERPCore.Domain.Entities.SalesInvoicePayment", b =>
                 {
                     b.HasOne("ERPCore.Domain.Entities.User", "Creator")
                         .WithMany()
@@ -6639,57 +6750,15 @@ namespace ERPCore.Migrations
                         .OnDelete(DeleteBehavior.Restrict)
                         .IsRequired();
 
-                    b.HasOne("ERPCore.Domain.Entities.Customer", "Customer")
-                        .WithMany()
-                        .HasForeignKey("CustomerId")
-                        .OnDelete(DeleteBehavior.Restrict)
-                        .IsRequired();
-
-                    b.HasOne("ERPCore.Domain.Entities.ReasonCode", "ReasonCode")
-                        .WithMany()
-                        .HasForeignKey("ReasonCodeId")
-                        .OnDelete(DeleteBehavior.Restrict)
-                        .IsRequired();
-
-                    b.HasOne("ERPCore.Domain.Entities.Warehouse", "Warehouse")
-                        .WithMany()
-                        .HasForeignKey("WarehouseId")
+                    b.HasOne("ERPCore.Domain.Entities.SalesInvoice", "SalesInvoice")
+                        .WithMany("Payments")
+                        .HasForeignKey("SalesInvoiceId")
                         .OnDelete(DeleteBehavior.Restrict)
                         .IsRequired();
 
                     b.Navigation("Creator");
 
-                    b.Navigation("Customer");
-
-                    b.Navigation("ReasonCode");
-
-                    b.Navigation("Warehouse");
-                });
-
-            modelBuilder.Entity("ERPCore.Domain.Entities.SalesReturnLine", b =>
-                {
-                    b.HasOne("ERPCore.Domain.Entities.Item", "Item")
-                        .WithMany()
-                        .HasForeignKey("ItemId")
-                        .OnDelete(DeleteBehavior.Restrict)
-                        .IsRequired();
-
-                    b.HasOne("ERPCore.Domain.Entities.SalesReturn", "Return")
-                        .WithMany("Lines")
-                        .HasForeignKey("ReturnId")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
-
-                    b.HasOne("ERPCore.Domain.Entities.SalesInvoiceLine", "SalesInvoiceLine")
-                        .WithMany()
-                        .HasForeignKey("SalesInvoiceLineId")
-                        .OnDelete(DeleteBehavior.Restrict);
-
-                    b.Navigation("Item");
-
-                    b.Navigation("Return");
-
-                    b.Navigation("SalesInvoiceLine");
+                    b.Navigation("SalesInvoice");
                 });
 
             modelBuilder.Entity("ERPCore.Domain.Entities.SalesReturn", b =>
@@ -6767,6 +6836,11 @@ namespace ERPCore.Migrations
                         .OnDelete(DeleteBehavior.Restrict)
                         .IsRequired();
 
+                    b.HasOne("ERPCore.Domain.Entities.SalesDayEnd", "DayEnd")
+                        .WithMany("Slips")
+                        .HasForeignKey("DayEndId")
+                        .OnDelete(DeleteBehavior.Restrict);
+
                     b.HasOne("ERPCore.Domain.Entities.Warehouse", "Warehouse")
                         .WithMany()
                         .HasForeignKey("WarehouseId")
@@ -6777,6 +6851,8 @@ namespace ERPCore.Migrations
 
                     b.Navigation("Customer");
 
+                    b.Navigation("DayEnd");
+
                     b.Navigation("Warehouse");
                 });
 
@@ -7259,11 +7335,6 @@ namespace ERPCore.Migrations
                     b.Navigation("WarrantyNumbers");
                 });
 
-            modelBuilder.Entity("ERPCore.Domain.Entities.GrnLine", b =>
-                {
-                    b.Navigation("WarrantyNumbers");
-                });
-
             modelBuilder.Entity("ERPCore.Domain.Entities.Item", b =>
                 {
                     b.Navigation("ReorderSettings");
@@ -7333,14 +7404,18 @@ namespace ERPCore.Migrations
                     b.Navigation("Outputs");
                 });
 
+            modelBuilder.Entity("ERPCore.Domain.Entities.SalesDayEnd", b =>
+                {
+                    b.Navigation("BundleSales");
+
+                    b.Navigation("Slips");
+                });
+
             modelBuilder.Entity("ERPCore.Domain.Entities.SalesInvoice", b =>
                 {
                     b.Navigation("Lines");
-                });
 
-            modelBuilder.Entity("ERPCore.Domain.Entities.SalesReturn", b =>
-                {
-                    b.Navigation("Lines");
+                    b.Navigation("Payments");
                 });
 
             modelBuilder.Entity("ERPCore.Domain.Entities.SalesReturn", b =>

Backend/ERPCore/Program.cs

@@ -112,11 +112,13 @@ builder.Services.AddScoped<ISalesPostingService, SalesPostingService>();
 builder.Services.AddScoped<ISalesDocumentWorkflowService, SalesDocumentWorkflowService>();
 builder.Services.AddScoped<ISalesMappingService, SalesMappingService>();
 builder.Services.AddScoped<ISalesInvoiceService, SalesInvoiceService>();
+builder.Services.AddScoped<ISalesInvoicePaymentService, SalesInvoicePaymentService>();
 builder.Services.AddScoped<ISalesSlipService, SalesSlipService>();
 builder.Services.AddScoped<IBundleSaleService, BundleSaleService>();
 builder.Services.AddScoped<ISalesPromotionSuggestionService, SalesPromotionSuggestionService>();
 builder.Services.AddScoped<ISalesReportService, SalesReportService>();
 builder.Services.AddScoped<ISalesReturnService, SalesReturnService>();
+builder.Services.AddScoped<ISalesDayEndService, SalesDayEndService>();
 
 // Stock transactions + reference data (docs/11 §5–6)
 builder.Services.AddScoped<IStockMutator, StockMutator>();

Backend/ERPCore/Services/AdjustmentService.cs

@@ -6,6 +6,7 @@ using ERPCore.Dtos.Stock;
 using ERPCore.Infra.Auth;
 using ERPCore.Infra.UoW;
 using ERPCore.Repositories.Interfaces;
+using ERPCore.Services.Gl;
 using ERPCore.Services.Interfaces;
 using ERPCore.System.Errors;
 using Microsoft.EntityFrameworkCore;
@@ -16,7 +17,10 @@ namespace ERPCore.Services;
 /// Stock-adjustment service — the highest-risk feature (02-SECURITY C.5). Auto-posts
 /// with a mandatory reason code and user stamp. Line application (FIFO consume on a
 /// decrease, layer create on an increase) + ledger posting is delegated to
-/// <see cref="IStockMutator"/>. Runs in a single UoW transaction (NFR-02/05).
+/// <see cref="IStockMutator"/>. Runs in a single UoW transaction (NFR-02/05). Also posts
+/// a real GL journal entry — increases and decreases post as separate Inventory/Gain and
+/// Loss/Inventory lines respectively (never netted against each other), so a count that's
+/// simultaneously over on one item and under on another shows both, not a false net.
 /// </summary>
 public sealed class AdjustmentService : IAdjustmentService
 {
@@ -29,11 +33,16 @@ public sealed class AdjustmentService : IAdjustmentService
     private readonly INumberSequenceService _numbers;
     private readonly ICurrentUser _currentUser;
     private readonly IUnitOfWork _uow;
+    private readonly IGeneralLedgerService _gl;
+    private readonly string _glInventoryAccountCode;
+    private readonly string _glGainAccountCode;
+    private readonly string _glLossAccountCode;
 
     public AdjustmentService(
         IRepository<StockAdjustment> adjustments, IRepository<Warehouse> warehouses, IRepository<Item> items,
         IRepository<ReasonCode> reasonCodes, IRepository<StockLedger> ledger, IStockMutator mutator,
-        INumberSequenceService numbers, ICurrentUser currentUser, IUnitOfWork uow)
+        INumberSequenceService numbers, ICurrentUser currentUser, IUnitOfWork uow,
+        IGeneralLedgerService gl, IConfiguration configuration)
     {
         _adjustments = adjustments;
         _warehouses = warehouses;
@@ -44,6 +53,45 @@ public sealed class AdjustmentService : IAdjustmentService
         _numbers = numbers;
         _currentUser = currentUser;
         _uow = uow;
+        _gl = gl;
+        _glInventoryAccountCode = configuration["Adjustment:GlInventoryAccountCode"] ?? string.Empty;
+        _glGainAccountCode = configuration["Adjustment:GlGainAccountCode"] ?? string.Empty;
+        _glLossAccountCode = configuration["Adjustment:GlLossAccountCode"] ?? string.Empty;
+    }
+
+    /// <summary>Builds and posts the GL journal for a <see cref="StockAdjustment"/>'s stock movement.
+    /// <see cref="CountService"/>'s variance posting mirrors this exact logic for the same reason
+    /// (it creates a <see cref="StockAdjustment"/> through the same <see cref="IStockMutator"/> call).</summary>
+    private async Task<string?> PostAdjustmentJournalAsync(
+        string docNo, DateTime now, IReadOnlyList<StockLedger> refs, CancellationToken ct)
+    {
+        var gain = refs.Where(r => r.Direction == Direction.In).Sum(r => r.Value);
+        var loss = refs.Where(r => r.Direction == Direction.Out).Sum(r => r.Value);
+        if (gain <= 0 && loss <= 0) return null;
+
+        var period = await _gl.GetPeriodByDateAsync(DateOnly.FromDateTime(now), ct);
+        var lines = new List<GlJournalEntryLineRequest>();
+        if (gain > 0)
+        {
+            lines.Add(new GlJournalEntryLineRequest(_glInventoryAccountCode, gain, 0m, $"Adjustment {docNo} — stock increase"));
+            lines.Add(new GlJournalEntryLineRequest(_glGainAccountCode, 0m, gain, $"Adjustment {docNo} — inventory gain"));
+        }
+        if (loss > 0)
+        {
+            lines.Add(new GlJournalEntryLineRequest(_glLossAccountCode, loss, 0m, $"Adjustment {docNo} — inventory loss"));
+            lines.Add(new GlJournalEntryLineRequest(_glInventoryAccountCode, 0m, loss, $"Adjustment {docNo} — stock decrease"));
+        }
+
+        var result = await _gl.PostJournalEntryAsync(new GlJournalEntryRequest
+        {
+            PeriodId = period.PeriodId,
+            EntryDate = DateOnly.FromDateTime(now),
+            SourceModule = "ADJUSTMENT",
+            Reference = docNo,
+            Narration = $"Stock adjustment {docNo}",
+            Lines = lines
+        }, ct);
+        return result.JournalNo;
     }
 
     public async Task<PagedResponse<AdjustmentSummaryDto>> ListAsync(
@@ -64,7 +112,7 @@ public sealed class AdjustmentService : IAdjustmentService
             .Skip(query.Skip).Take(query.PageSize)
             .Select(a => new AdjustmentSummaryDto(
                 a.AdjustmentId, a.DocNo, a.WarehouseId, a.ReasonCodeId, a.Status,
-                a.CreatedBy, a.CreatedAt, a.Lines.Count))
+                a.CreatedBy, a.CreatedAt, a.Lines.Count, a.GlJournalNo))
             .ToListAsync(ct);
 
         return PagedResponse<AdjustmentSummaryDto>.Create(rows, query.Page, query.PageSize, total);
@@ -136,6 +184,10 @@ public sealed class AdjustmentService : IAdjustmentService
             await _uow.SaveChangesAsync(token); // flush so AdjustmentId is a valid ledger sourceDocId
 
             var refs = await _mutator.ApplyAsync(request.WarehouseId, DocumentTypes.Adjustment, entity.AdjustmentId, now, deltas, token);
+
+            entity.GlJournalNo = await PostAdjustmentJournalAsync(docNo, now, refs, token);
+            if (entity.GlJournalNo is not null) entity.GlPostedAt = now;
+
             return (entity, refs);
         }, ct);
 
@@ -144,6 +196,7 @@ public sealed class AdjustmentService : IAdjustmentService
 
     private static AdjustmentDto ToDto(StockAdjustment a, IReadOnlyList<int> ledgerRefs) => new(
         a.AdjustmentId, a.DocNo, a.WarehouseId, a.ReasonCodeId, a.Status, a.CreatedBy, a.CreatedAt,
+        a.GlJournalNo, a.GlPostedAt,
         a.Lines.OrderBy(l => l.AdjLineId)
             .Select(l => new AdjustmentLineDto(l.AdjLineId, l.ItemId, l.BinId, l.BatchId, l.QtyDelta)).ToList(),
         ledgerRefs);

Backend/ERPCore/Services/BundleSaleService.cs

@@ -17,6 +17,7 @@ public sealed class BundleSaleService : IBundleSaleService
 {
     private readonly IRepository<BundleSaleTemplate> _templates;
     private readonly IRepository<BundleSale> _bundles;
+    private readonly IRepository<SalesDayEnd> _dayEnds;
     private readonly IRepository<Customer> _customers;
     private readonly IRepository<Item> _items;
     private readonly IRepository<Warehouse> _warehouses;
@@ -30,6 +31,7 @@ public sealed class BundleSaleService : IBundleSaleService
     public BundleSaleService(
         IRepository<BundleSale> bundles,
         IRepository<BundleSaleTemplate> templates,
+        IRepository<SalesDayEnd> dayEnds,
         IRepository<Customer> customers,
         IRepository<Item> items,
         IRepository<Warehouse> warehouses,
@@ -42,6 +44,7 @@ public sealed class BundleSaleService : IBundleSaleService
     {
         _templates = templates;
         _bundles = bundles;
+        _dayEnds = dayEnds;
         _customers = customers;
         _items = items;
         _warehouses = warehouses;
@@ -110,6 +113,15 @@ public sealed class BundleSaleService : IBundleSaleService
     public async Task<BundleSaleDto> CreateAsync(CreateBundleSaleRequest request, CancellationToken ct = default)
     {
         await _sales.ValidateSalesHeaderAsync(request.CustomerId, request.WarehouseId, request.CashierUserId, true, ct);
+
+        // Same guard as SalesSlipService.CreateAsync — a bundle sale is a cashier document
+        // exactly like a sales slip, so it's blocked by the same closed day (docs/14 Sales Day End).
+        var today = DateOnly.FromDateTime(DateTime.UtcNow);
+        var alreadyClosed = await _dayEnds.Query().AsNoTracking()
+            .AnyAsync(x => x.CashierUserId == request.CashierUserId && x.BusinessDate == today, ct);
+        if (alreadyClosed)
+            throw new ConflictException($"Cashier {request.CashierUserId} already closed today's ({today:yyyy-MM-dd}) sales — day-end has been posted.");
+
         var template = await _templates.Query().AsNoTracking().Include(x => x.Lines)
             .FirstAsync(x => x.BundleSaleTemplateId == request.BundleSaleTemplateId, ct);
         var bundle = new BundleSale

Backend/ERPCore/Services/CountService.cs

@@ -6,6 +6,7 @@ using ERPCore.Dtos.Stock;
 using ERPCore.Infra.Auth;
 using ERPCore.Infra.UoW;
 using ERPCore.Repositories.Interfaces;
+using ERPCore.Services.Gl;
 using ERPCore.Services.Interfaces;
 using ERPCore.System.Errors;
 using Microsoft.EntityFrameworkCore;
@@ -16,7 +17,9 @@ namespace ERPCore.Services;
 /// Stock-count service (FR-STK-08). Create snapshots system quantities (immutable,
 /// 02-SECURITY C.7); posting emits a variance <see cref="StockAdjustment"/> via the
 /// shared <see cref="IStockMutator"/> (a variance is an adjustment in disguise, C.7)
-/// and closes the count — all in one UoW transaction.
+/// and closes the count — all in one UoW transaction. GL posting for that variance
+/// mirrors <see cref="AdjustmentService"/>'s (same account config, same gain/loss
+/// split) since it's the exact same kind of document under the hood.
 /// </summary>
 public sealed class CountService : ICountService
 {
@@ -32,11 +35,16 @@ public sealed class CountService : ICountService
     private readonly INumberSequenceService _numbers;
     private readonly ICurrentUser _currentUser;
     private readonly IUnitOfWork _uow;
+    private readonly IGeneralLedgerService _gl;
+    private readonly string _glInventoryAccountCode;
+    private readonly string _glGainAccountCode;
+    private readonly string _glLossAccountCode;
 
     public CountService(
         IRepository<StockCount> counts, IRepository<StockAdjustment> adjustments, IRepository<Warehouse> warehouses,
         IRepository<Item> items, IRepository<ReasonCode> reasonCodes, IFifoCostingService fifo, IStockMutator mutator,
-        INumberSequenceService numbers, ICurrentUser currentUser, IUnitOfWork uow)
+        INumberSequenceService numbers, ICurrentUser currentUser, IUnitOfWork uow,
+        IGeneralLedgerService gl, IConfiguration configuration)
     {
         _counts = counts;
         _adjustments = adjustments;
@@ -48,6 +56,44 @@ public sealed class CountService : ICountService
         _numbers = numbers;
         _currentUser = currentUser;
         _uow = uow;
+        _gl = gl;
+        _glInventoryAccountCode = configuration["Adjustment:GlInventoryAccountCode"] ?? string.Empty;
+        _glGainAccountCode = configuration["Adjustment:GlGainAccountCode"] ?? string.Empty;
+        _glLossAccountCode = configuration["Adjustment:GlLossAccountCode"] ?? string.Empty;
+    }
+
+    /// <summary>Same logic as <c>AdjustmentService</c>'s private method of the same name — see there for why
+    /// gains/losses post as separate lines instead of a net.</summary>
+    private async Task<string?> PostAdjustmentJournalAsync(
+        string docNo, DateTime now, IReadOnlyList<StockLedger> refs, CancellationToken ct)
+    {
+        var gain = refs.Where(r => r.Direction == Direction.In).Sum(r => r.Value);
+        var loss = refs.Where(r => r.Direction == Direction.Out).Sum(r => r.Value);
+        if (gain <= 0 && loss <= 0) return null;
+
+        var period = await _gl.GetPeriodByDateAsync(DateOnly.FromDateTime(now), ct);
+        var lines = new List<GlJournalEntryLineRequest>();
+        if (gain > 0)
+        {
+            lines.Add(new GlJournalEntryLineRequest(_glInventoryAccountCode, gain, 0m, $"Adjustment {docNo} — stock increase"));
+            lines.Add(new GlJournalEntryLineRequest(_glGainAccountCode, 0m, gain, $"Adjustment {docNo} — inventory gain"));
+        }
+        if (loss > 0)
+        {
+            lines.Add(new GlJournalEntryLineRequest(_glLossAccountCode, loss, 0m, $"Adjustment {docNo} — inventory loss"));
+            lines.Add(new GlJournalEntryLineRequest(_glInventoryAccountCode, 0m, loss, $"Adjustment {docNo} — stock decrease"));
+        }
+
+        var result = await _gl.PostJournalEntryAsync(new GlJournalEntryRequest
+        {
+            PeriodId = period.PeriodId,
+            EntryDate = DateOnly.FromDateTime(now),
+            SourceModule = "ADJUSTMENT",
+            Reference = docNo,
+            Narration = $"Stock adjustment {docNo}",
+            Lines = lines
+        }, ct);
+        return result.JournalNo;
     }
 
     public async Task<PagedResponse<CountSummaryDto>> ListAsync(
@@ -160,7 +206,7 @@ public sealed class CountService : ICountService
         {
             count.Status = CountStatus.Posted;
             await _uow.SaveChangesAsync(ct);
-            return new CountPostResultDto(count.CountId, count.Status, null, Array.Empty<int>());
+            return new CountPostResultDto(count.CountId, count.Status, null, null, Array.Empty<int>());
         }
 
         var reason = await _reasonCodes.Query().AsNoTracking()
@@ -168,7 +214,7 @@ public sealed class CountService : ICountService
             ?? throw new DomainException(ErrorCodes.Validation, $"Reason code '{VarianceReasonCode}' (Count Variance) is not configured.", 422);
 
         var now = DateTime.UtcNow;
-        var (adjustmentId, ledgerEntries) = await _uow.ExecuteInTransactionAsync(async token =>
+        var (adjustmentId, glJournalNo, ledgerEntries) = await _uow.ExecuteInTransactionAsync(async token =>
         {
             var docNo = await _numbers.NextAsync(DocumentTypes.Adjustment, token);
             var adjustment = new StockAdjustment
@@ -191,12 +237,15 @@ public sealed class CountService : ICountService
 
             var refs = await _mutator.ApplyAsync(count.WarehouseId, DocumentTypes.Adjustment, adjustment.AdjustmentId, now, deltas, token);
 
+            adjustment.GlJournalNo = await PostAdjustmentJournalAsync(docNo, now, refs, token);
+            if (adjustment.GlJournalNo is not null) adjustment.GlPostedAt = now;
+
             count.Status = CountStatus.Posted;
-            return (adjustment.AdjustmentId, refs);
+            return (adjustment.AdjustmentId, adjustment.GlJournalNo, refs);
         }, ct);
 
         // Map ledger ids after commit so they are populated.
-        return new CountPostResultDto(count.CountId, count.Status, adjustmentId, ledgerEntries.Select(r => r.LedgerId).ToList());
+        return new CountPostResultDto(count.CountId, count.Status, adjustmentId, glJournalNo, ledgerEntries.Select(r => r.LedgerId).ToList());
     }
 
     private static CountDto Map(StockCount c) => new(

Backend/ERPCore/Services/Interfaces/ISalesDayEndService.cs

@@ -0,0 +1,20 @@
+using ERPCore.Dtos.Common;
+using ERPCore.Dtos.Sales;
+
+namespace ERPCore.Services.Interfaces;
+
+public interface ISalesDayEndService
+{
+    /// <summary>What closing <paramref name="businessDate"/> for this cashier would include right now
+    /// (or the already-closed record's totals, if it's already closed).</summary>
+    Task<SalesDayEndPreviewDto> PreviewAsync(int cashierUserId, DateOnly businessDate, CancellationToken ct = default);
+
+    /// <summary>Closes the day: locks every Posted slip for (CashierUserId, BusinessDate) against this
+    /// record and posts one consolidated GL journal entry. Idempotent — a second call for an
+    /// already-closed date replays the existing record rather than erroring.</summary>
+    Task<SalesDayEndDto> CloseAsync(CreateSalesDayEndRequest request, CancellationToken ct = default);
+
+    Task<PagedResponse<SalesDayEndSummaryDto>> ListAsync(PageQuery query, int? cashierUserId, CancellationToken ct = default);
+
+    Task<SalesDayEndDto?> GetAsync(int salesDayEndId, CancellationToken ct = default);
+}

Backend/ERPCore/Services/Interfaces/ISalesInvoicePaymentService.cs

@@ -0,0 +1,10 @@
+using ERPCore.Dtos.Sales;
+
+namespace ERPCore.Services.Interfaces;
+
+/// <summary>Customer payments against a Posted sales invoice's balance (installments allowed).</summary>
+public interface ISalesInvoicePaymentService
+{
+    Task<SalesInvoicePaymentDto> PayAsync(int salesInvoiceId, CreateSalesInvoicePaymentRequest request, CancellationToken ct = default);
+    Task<IReadOnlyList<SalesInvoicePaymentDto>> ListAsync(int salesInvoiceId, CancellationToken ct = default);
+}

Backend/ERPCore/Services/Production/ProductionRunService.cs

@@ -16,6 +16,17 @@ namespace ERPCore.Services.Production;
 
 /// <summary>
 /// Production run lifecycle (docs/30 §D.2–D.3, FR-MFG-08..19).
+///
+/// Deliberately posts no GL journal entry anywhere in this file, for the same reason
+/// as <see cref="TransferService"/>: every movement here — raw material consumed
+/// (<see cref="StartStageAsync"/>), finished goods received (<see cref="PostReceiptAsync"/>),
+/// leftovers/cancellation returned to stock — stays inside the single shared Inventory
+/// GL account (raw materials, WIP, and finished goods are not separate GL accounts in
+/// this chart of accounts). And unlike a real write-off, scrap here is never removed
+/// from the cost pool — <see cref="PostReceiptAsync"/> divides the full consumed value
+/// by the GOOD quantity only, so a scrapped unit's cost is absorbed into the surviving
+/// units' cost rather than expensed. So there is no value entering, leaving, or being
+/// destroyed anywhere in a run — nothing for a journal entry to say.
 /// </summary>
 public sealed class ProductionRunService : IProductionRunService
 {

Backend/ERPCore/Services/PurchaseReturnService.cs

@@ -6,6 +6,7 @@ using ERPCore.Dtos.Procurement;
 using ERPCore.Infra.Auth;
 using ERPCore.Infra.UoW;
 using ERPCore.Repositories.Interfaces;
+using ERPCore.Services.Gl;
 using ERPCore.Services.Interfaces;
 using ERPCore.System.Errors;
 using Microsoft.EntityFrameworkCore;
@@ -16,7 +17,9 @@ namespace ERPCore.Services;
 /// Purchase-return service (FR-PROC-08). Auto-posts with a mandatory Return reason
 /// code and generates an outbound stock movement via the shared
 /// <see cref="IStockMutator"/> (FIFO consume, row-locked; over-return beyond
-/// available → STOCK_NEGATIVE_BLOCKED). Single UoW transaction.
+/// available → STOCK_NEGATIVE_BLOCKED). Single UoW transaction. Also posts a real GL
+/// journal entry reversing the Inventory/Clearing lines the original <see cref="Grn"/>
+/// posted — reuses <c>Grn</c>'s own account config since it's reversing that posting.
 /// </summary>
 public sealed class PurchaseReturnService : IPurchaseReturnService
 {
@@ -31,12 +34,15 @@ public sealed class PurchaseReturnService : IPurchaseReturnService
     private readonly INumberSequenceService _numbers;
     private readonly ICurrentUser _currentUser;
     private readonly IUnitOfWork _uow;
+    private readonly IGeneralLedgerService _gl;
+    private readonly string _glInventoryAccountCode;
+    private readonly string _glClearingAccountCode;
 
     public PurchaseReturnService(
         IRepository<PurchaseReturn> returns, IRepository<Vendor> vendors, IRepository<Warehouse> warehouses,
         IRepository<Item> items, IRepository<ReasonCode> reasonCodes, IRepository<GrnLine> grnLines,
         IRepository<StockLedger> ledger, IStockMutator mutator, INumberSequenceService numbers,
-        ICurrentUser currentUser, IUnitOfWork uow)
+        ICurrentUser currentUser, IUnitOfWork uow, IGeneralLedgerService gl, IConfiguration configuration)
     {
         _returns = returns;
         _vendors = vendors;
@@ -49,6 +55,9 @@ public sealed class PurchaseReturnService : IPurchaseReturnService
         _numbers = numbers;
         _currentUser = currentUser;
         _uow = uow;
+        _gl = gl;
+        _glInventoryAccountCode = configuration["Grn:GlInventoryAccountCode"] ?? string.Empty;
+        _glClearingAccountCode = configuration["Grn:GlClearingAccountCode"] ?? string.Empty;
     }
 
     public async Task<PagedResponse<PurchaseReturnSummaryDto>> ListAsync(
@@ -69,7 +78,7 @@ public sealed class PurchaseReturnService : IPurchaseReturnService
             .Skip(query.Skip).Take(query.PageSize)
             .Select(r => new PurchaseReturnSummaryDto(
                 r.ReturnId, r.DocNo, r.VendorId, r.WarehouseId, r.ReasonCodeId, r.Status,
-                r.CreatedBy, r.CreatedAt, r.Lines.Count))
+                r.CreatedBy, r.CreatedAt, r.Lines.Count, r.GlJournalNo))
             .ToListAsync(ct);
 
         return PagedResponse<PurchaseReturnSummaryDto>.Create(rows, query.Page, query.PageSize, total);
@@ -146,6 +155,28 @@ public sealed class PurchaseReturnService : IPurchaseReturnService
             await _uow.SaveChangesAsync(token); // flush for a valid ledger sourceDocId
 
             var refs = await _mutator.ApplyAsync(request.WarehouseId, DocumentTypes.PurchaseReturn, ret.ReturnId, now, deltas, token);
+
+            var totalValue = refs.Sum(r => r.Value);
+            if (totalValue > 0)
+            {
+                var period = await _gl.GetPeriodByDateAsync(DateOnly.FromDateTime(now), token);
+                var glResult = await _gl.PostJournalEntryAsync(new GlJournalEntryRequest
+                {
+                    PeriodId = period.PeriodId,
+                    EntryDate = DateOnly.FromDateTime(now),
+                    SourceModule = "PURCHASE-RETURN",
+                    Reference = docNo,
+                    Narration = $"Purchase return {docNo} — stock returned to vendor",
+                    Lines = new List<GlJournalEntryLineRequest>
+                    {
+                        new(_glClearingAccountCode, totalValue, 0m, $"Purchase return {docNo}"),
+                        new(_glInventoryAccountCode, 0m, totalValue, $"Purchase return {docNo} — inventory reduction")
+                    }
+                }, token);
+                ret.GlJournalNo = glResult.JournalNo;
+                ret.GlPostedAt = now;
+            }
+
             return (ret, refs);
         }, ct);
 
@@ -155,6 +186,7 @@ public sealed class PurchaseReturnService : IPurchaseReturnService
 
     private static PurchaseReturnDto ToDto(PurchaseReturn r, IReadOnlyList<int> ledgerRefs) => new(
         r.ReturnId, r.DocNo, r.VendorId, r.WarehouseId, r.ReasonCodeId, r.Status, r.CreatedBy, r.CreatedAt,
+        r.GlJournalNo, r.GlPostedAt,
         r.Lines.OrderBy(l => l.ReturnLineId)
             .Select(l => new PurchaseReturnLineDto(l.ReturnLineId, l.GrnLineId, l.ItemId, l.Qty)).ToList(),
         ledgerRefs);

Backend/ERPCore/Services/SalesDayEndService.cs

@@ -0,0 +1,319 @@
+using ERPCore.Domain;
+using ERPCore.Domain.Entities;
+using ERPCore.Domain.Enums;
+using ERPCore.Dtos.Common;
+using ERPCore.Dtos.Sales;
+using ERPCore.Infra.Auth;
+using ERPCore.Infra.UoW;
+using ERPCore.Repositories.Interfaces;
+using ERPCore.Services.Gl;
+using ERPCore.Services.Interfaces;
+using ERPCore.System.Errors;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Configuration;
+
+namespace ERPCore.Services;
+
+/// <summary>
+/// Cashier day-end close-out. A day's <see cref="SalesSlip"/>s and <see cref="BundleSale"/>s —
+/// both cashier documents with the same Draft→Posted lifecycle, just priced differently — are
+/// rung up individually through the day with no GL impact of their own; <see cref="CloseAsync"/>
+/// is the single point where that day's sales become real accounting entries — one consolidated
+/// journal entry per cashier per day, mirroring how <see cref="GrnService"/> posts per receipt.
+/// Every document is treated as a cash sale (Debit Cash for GrandTotal): SalesSlip's
+/// PaidAmount/BalanceAmount fields exist for a future partial-payment flow but nothing
+/// sets them today (SalesSlipService.CreateAsync always leaves PaidAmount at 0), so
+/// they aren't a usable signal here — see docs/14-BACKEND-SALES-API.md if that changes.
+/// A bundle sale's net revenue is always exactly <c>BundlePrice</c> (<c>GrandTotal - TaxTotal</c>
+/// by construction, docs/15) regardless of whether the bundle sold at a discount or a premium to
+/// its component subtotal, so it folds into Subtotal/DiscountTotal the same way a slip's net
+/// (Subtotal - DiscountTotal) does, without a separate "bundle discount" GL line.
+/// </summary>
+public sealed class SalesDayEndService : ISalesDayEndService
+{
+    private readonly IRepository<SalesDayEnd> _dayEnds;
+    private readonly IRepository<SalesSlip> _slips;
+    private readonly IRepository<BundleSale> _bundles;
+    private readonly IRepository<StockLedger> _ledger;
+    private readonly IRepository<Item> _items;
+    private readonly INumberSequenceService _numbers;
+    private readonly ICurrentUser _currentUser;
+    private readonly IUnitOfWork _uow;
+    private readonly IGeneralLedgerService _gl;
+    private readonly string _glCashAccountCode;
+    private readonly string _glSalesRevenueAccountCode;
+    private readonly string _glSalesDiscountAccountCode;
+    private readonly string _glTaxPayableAccountCode;
+    private readonly string _glCogsAccountCode;
+    private readonly string _glInventoryAccountCode;
+
+    public SalesDayEndService(
+        IRepository<SalesDayEnd> dayEnds, IRepository<SalesSlip> slips, IRepository<BundleSale> bundles,
+        IRepository<StockLedger> ledger, IRepository<Item> items, INumberSequenceService numbers,
+        ICurrentUser currentUser, IUnitOfWork uow, IGeneralLedgerService gl, IConfiguration configuration)
+    {
+        _dayEnds = dayEnds;
+        _slips = slips;
+        _bundles = bundles;
+        _ledger = ledger;
+        _items = items;
+        _numbers = numbers;
+        _currentUser = currentUser;
+        _uow = uow;
+        _gl = gl;
+        _glCashAccountCode = configuration["SalesDayEnd:GlCashAccountCode"] ?? string.Empty;
+        _glSalesRevenueAccountCode = configuration["SalesDayEnd:GlSalesRevenueAccountCode"] ?? string.Empty;
+        _glSalesDiscountAccountCode = configuration["SalesDayEnd:GlSalesDiscountAccountCode"] ?? string.Empty;
+        _glTaxPayableAccountCode = configuration["SalesDayEnd:GlTaxPayableAccountCode"] ?? string.Empty;
+        _glCogsAccountCode = configuration["SalesDayEnd:GlCogsAccountCode"] ?? string.Empty;
+        _glInventoryAccountCode = configuration["SalesDayEnd:GlInventoryAccountCode"] ?? string.Empty;
+    }
+
+    public async Task<SalesDayEndPreviewDto> PreviewAsync(int cashierUserId, DateOnly businessDate, CancellationToken ct = default)
+    {
+        var existing = await _dayEnds.Query().AsNoTracking()
+            .FirstOrDefaultAsync(x => x.CashierUserId == cashierUserId && x.BusinessDate == businessDate, ct);
+        if (existing is not null)
+        {
+            var closedSlipNumbers = await _slips.Query().AsNoTracking()
+                .Where(x => x.DayEndId == existing.SalesDayEndId)
+                .OrderBy(x => x.SlipNo)
+                .Select(x => x.SlipNo)
+                .ToListAsync(ct);
+            var closedBundleNumbers = await _bundles.Query().AsNoTracking()
+                .Where(x => x.DayEndId == existing.SalesDayEndId)
+                .OrderBy(x => x.BundleNo)
+                .Select(x => x.BundleNo)
+                .ToListAsync(ct);
+            return new SalesDayEndPreviewDto(
+                cashierUserId, businessDate, true,
+                existing.SlipCount, existing.BundleCount, existing.Subtotal, existing.DiscountTotal, existing.TaxTotal, existing.GrandTotal,
+                closedSlipNumbers, closedBundleNumbers,
+                Array.Empty<DraftSlipBlockingCloseDto>(), Array.Empty<DraftBundleBlockingCloseDto>());
+        }
+
+        var openSlips = await LoadOpenSlipsAsync(cashierUserId, businessDate, ct);
+        var postedSlips = openSlips.Where(x => x.Status == SalesSlipStatus.Posted).ToList();
+        var draftSlips = openSlips.Where(x => x.Status == SalesSlipStatus.Draft).ToList();
+
+        var openBundles = await LoadOpenBundleSalesAsync(cashierUserId, businessDate, ct);
+        var postedBundles = openBundles.Where(x => x.Status == BundleSaleStatus.Posted).ToList();
+        var draftBundles = openBundles.Where(x => x.Status == BundleSaleStatus.Draft).ToList();
+
+        var subtotal = postedSlips.Sum(x => x.Subtotal) + postedBundles.Sum(x => x.BundlePrice);
+        var discountTotal = postedSlips.Sum(x => x.DiscountTotal);
+        var taxTotal = postedSlips.Sum(x => x.TaxTotal) + postedBundles.Sum(x => x.TaxTotal);
+        var grandTotal = postedSlips.Sum(x => x.GrandTotal) + postedBundles.Sum(x => x.GrandTotal);
+
+        return new SalesDayEndPreviewDto(
+            cashierUserId, businessDate, false,
+            postedSlips.Count, postedBundles.Count, subtotal, discountTotal, taxTotal, grandTotal,
+            postedSlips.OrderBy(x => x.SlipNo).Select(x => x.SlipNo).ToList(),
+            postedBundles.OrderBy(x => x.BundleNo).Select(x => x.BundleNo).ToList(),
+            draftSlips.OrderBy(x => x.SlipNo).Select(x => new DraftSlipBlockingCloseDto(x.SalesSlipId, x.SlipNo, x.GrandTotal)).ToList(),
+            draftBundles.OrderBy(x => x.BundleNo).Select(x => new DraftBundleBlockingCloseDto(x.BundleSaleId, x.BundleNo, x.GrandTotal)).ToList());
+    }
+
+    public async Task<SalesDayEndDto> CloseAsync(CreateSalesDayEndRequest request, CancellationToken ct = default)
+    {
+        var businessDate = request.BusinessDate ?? DateOnly.FromDateTime(DateTime.UtcNow);
+
+        // Idempotent replay (same pattern as GrnService.ConfirmAsync): closing an
+        // already-closed date returns the existing record instead of erroring.
+        var existing = await _dayEnds.Query()
+            .FirstOrDefaultAsync(x => x.CashierUserId == request.CashierUserId && x.BusinessDate == businessDate, ct);
+        if (existing is not null)
+            return await BuildDtoAsync(existing, ct);
+
+        var openSlips = await LoadOpenSlipsAsync(request.CashierUserId, businessDate, ct);
+        var draftSlips = openSlips.Where(x => x.Status == SalesSlipStatus.Draft).ToList();
+        var openBundles = await LoadOpenBundleSalesAsync(request.CashierUserId, businessDate, ct);
+        var draftBundles = openBundles.Where(x => x.Status == BundleSaleStatus.Draft).ToList();
+
+        if (draftSlips.Count > 0 || draftBundles.Count > 0)
+        {
+            var parts = new List<string>();
+            if (draftSlips.Count > 0)
+                parts.Add($"{draftSlips.Count} sales slip(s): " + string.Join(", ", draftSlips.OrderBy(x => x.SlipNo).Select(x => x.SlipNo)));
+            if (draftBundles.Count > 0)
+                parts.Add($"{draftBundles.Count} bundle sale(s): " + string.Join(", ", draftBundles.OrderBy(x => x.BundleNo).Select(x => x.BundleNo)));
+            throw new ConflictException(
+                "Still Draft for this cashier/date — post or cancel them before closing the day: " + string.Join("; ", parts));
+        }
+
+        var postedSlips = openSlips.Where(x => x.Status == SalesSlipStatus.Posted).ToList();
+        var settledSlips = openSlips.Where(x => x.Status != SalesSlipStatus.Draft).ToList(); // Posted + Cancelled — everything gets frozen against this close
+        var postedBundles = openBundles.Where(x => x.Status == BundleSaleStatus.Posted).ToList();
+        var settledBundles = openBundles.Where(x => x.Status != BundleSaleStatus.Draft).ToList();
+
+        var subtotal = postedSlips.Sum(x => x.Subtotal) + postedBundles.Sum(x => x.BundlePrice);
+        var discountTotal = postedSlips.Sum(x => x.DiscountTotal);
+        var taxTotal = postedSlips.Sum(x => x.TaxTotal) + postedBundles.Sum(x => x.TaxTotal);
+        var grandTotal = postedSlips.Sum(x => x.GrandTotal) + postedBundles.Sum(x => x.GrandTotal);
+
+        var slipIds = postedSlips.Select(x => x.SalesSlipId).ToList();
+        var bundleIds = postedBundles.Select(x => x.BundleSaleId).ToList();
+        var slipCogs = slipIds.Count == 0
+            ? 0m
+            : await _ledger.Query().AsNoTracking()
+                .Where(l => l.SourceDocType == DocumentTypes.SalesSlip && slipIds.Contains(l.SourceDocId) && l.Direction == Direction.Out)
+                .SumAsync(l => l.Value, ct);
+        var bundleCogs = bundleIds.Count == 0
+            ? 0m
+            : await _ledger.Query().AsNoTracking()
+                .Where(l => l.SourceDocType == DocumentTypes.BundleSale && bundleIds.Contains(l.SourceDocId) && l.Direction == Direction.Out)
+                .SumAsync(l => l.Value, ct);
+        var cogs = slipCogs + bundleCogs;
+
+        var dayEnd = await _uow.ExecuteInTransactionAsync(async token =>
+        {
+            var now = DateTime.UtcNow;
+            var docNo = await _numbers.NextAsync(DocumentTypes.SalesDayEnd, token);
+            var entity = new SalesDayEnd
+            {
+                DocNo = docNo,
+                CashierUserId = request.CashierUserId,
+                BusinessDate = businessDate,
+                SlipCount = postedSlips.Count,
+                BundleCount = postedBundles.Count,
+                Subtotal = subtotal,
+                DiscountTotal = discountTotal,
+                TaxTotal = taxTotal,
+                GrandTotal = grandTotal,
+                CostOfGoodsSold = cogs,
+                ClosedBy = _currentUser.AuditUserId,
+                ClosedAt = now
+            };
+
+            if (grandTotal > 0 || cogs > 0)
+            {
+                var period = await _gl.GetPeriodByDateAsync(businessDate, token);
+                var glLines = new List<GlJournalEntryLineRequest>();
+                if (grandTotal > 0)
+                {
+                    glLines.Add(new GlJournalEntryLineRequest(_glCashAccountCode, grandTotal, 0m, $"Day-end {businessDate:yyyy-MM-dd} cashier {request.CashierUserId} — cash collected"));
+                    if (discountTotal > 0)
+                        glLines.Add(new GlJournalEntryLineRequest(_glSalesDiscountAccountCode, discountTotal, 0m, "Sales discount"));
+                    glLines.Add(new GlJournalEntryLineRequest(_glSalesRevenueAccountCode, 0m, subtotal, "Sales revenue"));
+                    if (taxTotal > 0)
+                        glLines.Add(new GlJournalEntryLineRequest(_glTaxPayableAccountCode, 0m, taxTotal, "Output tax payable"));
+                }
+                if (cogs > 0)
+                {
+                    glLines.Add(new GlJournalEntryLineRequest(_glCogsAccountCode, cogs, 0m, "Cost of goods sold"));
+                    glLines.Add(new GlJournalEntryLineRequest(_glInventoryAccountCode, 0m, cogs, "Inventory reduction"));
+                }
+
+                var glResult = await _gl.PostJournalEntryAsync(new GlJournalEntryRequest
+                {
+                    PeriodId = period.PeriodId,
+                    EntryDate = businessDate,
+                    SourceModule = "SALES-DAYEND",
+                    Reference = docNo,
+                    Narration = $"Cashier day-end {docNo} — {businessDate:yyyy-MM-dd}",
+                    Lines = glLines
+                }, token);
+                entity.GlJournalNo = glResult.JournalNo;
+                entity.GlPostedAt = now;
+            }
+
+            // Relationship fixup, not a direct FK assignment: `entity` has no real id yet
+            // (assigned by SaveChangesAsync inside ExecuteInTransactionAsync) — EF resolves
+            // the FK on these already-tracked rows from the navigation once it does, so the
+            // day-end row and every slip's/bundle's DayEndId commit together in one transaction.
+            foreach (var slip in settledSlips) slip.DayEnd = entity;
+            foreach (var bundle in settledBundles) bundle.DayEnd = entity;
+
+            await _dayEnds.AddAsync(entity, token);
+            return entity;
+        }, ct);
+
+        return await BuildDtoAsync(dayEnd, ct);
+    }
+
+    public async Task<PagedResponse<SalesDayEndSummaryDto>> ListAsync(PageQuery query, int? cashierUserId, CancellationToken ct = default)
+    {
+        var q = _dayEnds.Query().AsNoTracking();
+        if (cashierUserId is not null) q = q.Where(x => x.CashierUserId == cashierUserId);
+
+        var total = await q.CountAsync(ct);
+        var rows = await q.OrderByDescending(x => x.SalesDayEndId).Skip(query.Skip).Take(query.PageSize).ToListAsync(ct);
+        var items = rows.Select(x => new SalesDayEndSummaryDto(
+            x.SalesDayEndId, x.DocNo, x.CashierUserId, x.BusinessDate, x.SlipCount, x.BundleCount, x.GrandTotal, x.GlJournalNo, x.ClosedAt)).ToList();
+        return PagedResponse<SalesDayEndSummaryDto>.Create(items, query.Page, query.PageSize, total);
+    }
+
+    public async Task<SalesDayEndDto?> GetAsync(int salesDayEndId, CancellationToken ct = default)
+    {
+        var entity = await _dayEnds.Query().AsNoTracking().FirstOrDefaultAsync(x => x.SalesDayEndId == salesDayEndId, ct);
+        return entity is null ? null : await BuildDtoAsync(entity, ct);
+    }
+
+    private async Task<List<SalesSlip>> LoadOpenSlipsAsync(int cashierUserId, DateOnly businessDate, CancellationToken ct)
+    {
+        var (dayStart, dayEnd) = DayRangeUtc(businessDate);
+        return await _slips.Query()
+            .Where(x => x.CashierUserId == cashierUserId && x.DayEndId == null && x.SlipDate >= dayStart && x.SlipDate < dayEnd)
+            .ToListAsync(ct);
+    }
+
+    private async Task<List<BundleSale>> LoadOpenBundleSalesAsync(int cashierUserId, DateOnly businessDate, CancellationToken ct)
+    {
+        var (dayStart, dayEnd) = DayRangeUtc(businessDate);
+        return await _bundles.Query()
+            .Where(x => x.CashierUserId == cashierUserId && x.DayEndId == null && x.BundleDate >= dayStart && x.BundleDate < dayEnd)
+            .ToListAsync(ct);
+    }
+
+    // SlipDate/BundleDate are stored as DateTime.UtcNow (Kind=Utc) throughout — Npgsql requires
+    // a matching Kind=Utc here too, or comparisons against the `timestamptz` column throw.
+    private static (DateTime Start, DateTime End) DayRangeUtc(DateOnly businessDate)
+    {
+        var start = DateTime.SpecifyKind(businessDate.ToDateTime(TimeOnly.MinValue), DateTimeKind.Utc);
+        return (start, start.AddDays(1));
+    }
+
+    private async Task<SalesDayEndDto> BuildDtoAsync(SalesDayEnd entity, CancellationToken ct)
+    {
+        var postedSlips = await _slips.Query().AsNoTracking().Include(x => x.Lines)
+            .Where(x => x.DayEndId == entity.SalesDayEndId && x.Status == SalesSlipStatus.Posted)
+            .ToListAsync(ct);
+        var postedBundles = await _bundles.Query().AsNoTracking().Include(x => x.Lines)
+            .Where(x => x.DayEndId == entity.SalesDayEndId && x.Status == BundleSaleStatus.Posted)
+            .ToListAsync(ct);
+
+        var slipNumbers = postedSlips.OrderBy(x => x.SlipNo).Select(x => x.SlipNo).ToList();
+        var bundleNumbers = postedBundles.OrderBy(x => x.BundleNo).Select(x => x.BundleNo).ToList();
+
+        var slipQtyRevenue = postedSlips.SelectMany(x => x.Lines)
+            .GroupBy(l => l.ItemId)
+            .Select(g => new { ItemId = g.Key, Qty = g.Sum(l => l.Qty + l.FreeQty), Revenue = g.Sum(l => l.LineTotal) });
+        var bundleQtyRevenue = postedBundles.SelectMany(x => x.Lines)
+            .GroupBy(l => l.ItemId)
+            .Select(g => new { ItemId = g.Key, Qty = g.Sum(l => l.Qty), Revenue = g.Sum(l => l.LineTotal) });
+
+        var grouped = slipQtyRevenue.Concat(bundleQtyRevenue)
+            .GroupBy(x => x.ItemId)
+            .Select(g => new { ItemId = g.Key, Qty = g.Sum(x => x.Qty), Revenue = g.Sum(x => x.Revenue) })
+            .ToList();
+        var itemIds = grouped.Select(g => g.ItemId).ToList();
+        var itemInfo = await _items.Query().AsNoTracking()
+            .Where(i => itemIds.Contains(i.ItemId))
+            .Select(i => new { i.ItemId, i.Sku, i.Name })
+            .ToListAsync(ct);
+        var breakdown = grouped
+            .Select(g =>
+            {
+                var info = itemInfo.FirstOrDefault(i => i.ItemId == g.ItemId);
+                return new SalesDayEndItemLineDto(g.ItemId, info?.Sku ?? $"SKU-{g.ItemId}", info?.Name ?? "—", g.Qty, g.Revenue);
+            })
+            .OrderByDescending(x => x.Revenue)
+            .ToList();
+
+        return new SalesDayEndDto(
+            entity.SalesDayEndId, entity.DocNo, entity.CashierUserId, entity.BusinessDate,
+            entity.SlipCount, entity.BundleCount, entity.Subtotal, entity.DiscountTotal, entity.TaxTotal, entity.GrandTotal,
+            entity.CostOfGoodsSold, entity.GlJournalNo, entity.GlPostedAt, entity.ClosedBy, entity.ClosedAt,
+            slipNumbers, bundleNumbers, breakdown);
+    }
+}

Backend/ERPCore/Services/SalesInvoicePaymentService.cs

@@ -0,0 +1,122 @@
+using ERPCore.Domain.Entities;
+using ERPCore.Domain.Enums;
+using ERPCore.Dtos.Sales;
+using ERPCore.Infra.Auth;
+using ERPCore.Infra.UoW;
+using ERPCore.Repositories.Interfaces;
+using ERPCore.Services.Gl;
+using ERPCore.Services.Interfaces;
+using ERPCore.System.Errors;
+using Microsoft.EntityFrameworkCore;
+
+namespace ERPCore.Services;
+
+/// <summary>
+/// Customer payments against a Posted sales invoice. Multiple installments are allowed
+/// until <see cref="SalesInvoice.BalanceAmount"/> reaches zero. Each payment posts its
+/// own real GL journal entry (Debit the selected bank-or-cash account / Credit Accounts
+/// Receivable) before being recorded, using the same call-GL-before-commit pattern as
+/// <see cref="GrnPaymentService"/> — the mirror image of it (that one credits a payable
+/// clearing account when vendor-paid; this one credits the receivable asset when
+/// customer-paid) — so a rejected/unreachable GL post rolls back the whole payment atomically.
+/// </summary>
+public sealed class SalesInvoicePaymentService : ISalesInvoicePaymentService
+{
+    private readonly IRepository<SalesInvoice> _invoices;
+    private readonly IRepository<SalesInvoicePayment> _payments;
+    private readonly IGeneralLedgerService _gl;
+    private readonly ICurrentUser _currentUser;
+    private readonly IUnitOfWork _uow;
+    private readonly string _glAccountsReceivableCode;
+
+    public SalesInvoicePaymentService(
+        IRepository<SalesInvoice> invoices, IRepository<SalesInvoicePayment> payments, IGeneralLedgerService gl,
+        ICurrentUser currentUser, IUnitOfWork uow, IConfiguration configuration)
+    {
+        _invoices = invoices;
+        _payments = payments;
+        _gl = gl;
+        _currentUser = currentUser;
+        _uow = uow;
+        _glAccountsReceivableCode = configuration["SalesInvoice:GlAccountsReceivableCode"] ?? string.Empty;
+    }
+
+    public async Task<SalesInvoicePaymentDto> PayAsync(int salesInvoiceId, CreateSalesInvoicePaymentRequest request, CancellationToken ct = default)
+    {
+        var invoice = await _invoices.Query().FirstOrDefaultAsync(i => i.SalesInvoiceId == salesInvoiceId, ct)
+            ?? throw new NotFoundException($"Sales invoice {salesInvoiceId} was not found.");
+
+        if (invoice.Status != SalesInvoiceStatus.Posted)
+            throw new DomainException(ErrorCodes.SalesInvoiceNotPayable, $"Sales invoice {salesInvoiceId} must be posted before it can be paid.", 409);
+        if (request.Amount > invoice.BalanceAmount)
+            throw new DomainException(ErrorCodes.SalesInvoicePaymentExceedsBalance,
+                $"Payment amount {request.Amount} exceeds the remaining balance {invoice.BalanceAmount}.", 400);
+
+        var accounts = await _gl.ListBankAccountsAsync(ct);
+        var account = accounts.FirstOrDefault(a => a.AccountId == request.GlBankAccountId)
+            ?? throw new DomainException(ErrorCodes.SalesInvoiceBankAccountNotFound, $"Bank/cash account {request.GlBankAccountId} was not found.", 404);
+
+        var actor = _currentUser.AuditUserId;
+        var now = DateTime.UtcNow;
+
+        var payment = await _uow.ExecuteInTransactionAsync(async token =>
+        {
+            // Same atomicity approach as GrnPaymentService.PayAsync: post to GL first, inside
+            // this transaction, before anything is committed — a GL rejection/timeout rolls
+            // the whole payment back with no partial local state.
+            var period = await _gl.GetPeriodByDateAsync(DateOnly.FromDateTime(now), token);
+            var posted = await _gl.PostJournalEntryAsync(new GlJournalEntryRequest
+            {
+                PeriodId = period.PeriodId,
+                EntryDate = DateOnly.FromDateTime(now),
+                SourceModule = "SALES_INVOICE_PAYMENT",
+                Reference = invoice.InvoiceNo,
+                Narration = $"Payment against invoice {invoice.InvoiceNo}",
+                Lines =
+                [
+                    new GlJournalEntryLineRequest(account.GlAccountCode, request.Amount, 0m, $"Payment against invoice {invoice.InvoiceNo}"),
+                    new GlJournalEntryLineRequest(_glAccountsReceivableCode, 0m, request.Amount, $"Payment against invoice {invoice.InvoiceNo}")
+                ]
+            }, token);
+
+            var entity = new SalesInvoicePayment
+            {
+                SalesInvoiceId = invoice.SalesInvoiceId,
+                Amount = request.Amount,
+                PaymentDate = now,
+                GlBankAccountId = account.AccountId,
+                BankAccountName = account.AccountName,
+                Reference = request.Reference,
+                GlJournalNo = posted.JournalNo,
+                CreatedBy = actor,
+                CreatedAt = now
+            };
+            await _payments.AddAsync(entity, token);
+
+            invoice.PaidAmount += request.Amount;
+            invoice.BalanceAmount -= request.Amount;
+
+            return entity;
+        }, ct);
+
+        return Map(payment);
+    }
+
+    public async Task<IReadOnlyList<SalesInvoicePaymentDto>> ListAsync(int salesInvoiceId, CancellationToken ct = default)
+    {
+        if (!await _invoices.Query().AnyAsync(i => i.SalesInvoiceId == salesInvoiceId, ct))
+            throw new NotFoundException($"Sales invoice {salesInvoiceId} was not found.");
+
+        return await _payments.Query().AsNoTracking()
+            .Where(p => p.SalesInvoiceId == salesInvoiceId)
+            .OrderByDescending(p => p.SalesInvoicePaymentId)
+            .Select(p => new SalesInvoicePaymentDto(
+                p.SalesInvoicePaymentId, p.SalesInvoiceId, p.Amount, p.PaymentDate,
+                p.GlBankAccountId, p.BankAccountName, p.Reference, p.GlJournalNo, p.CreatedAt))
+            .ToListAsync(ct);
+    }
+
+    private static SalesInvoicePaymentDto Map(SalesInvoicePayment p) => new(
+        p.SalesInvoicePaymentId, p.SalesInvoiceId, p.Amount, p.PaymentDate,
+        p.GlBankAccountId, p.BankAccountName, p.Reference, p.GlJournalNo, p.CreatedAt);
+}

Backend/ERPCore/Services/SalesInvoiceService.cs

@@ -80,24 +80,32 @@ public sealed class SalesInvoiceService : ISalesInvoiceService
     public async Task<ETagged<SalesInvoiceDto>> CreateAsync(CreateSalesInvoiceRequest request, CancellationToken ct = default)
     {
         await _sales.ValidateSalesHeaderAsync(request.CustomerId, request.WarehouseId, null, false, ct);
-        var invoice = new SalesInvoice
-        {
-            InvoiceNo = await _numbers.NextAsync(DocumentTypes.SalesInvoice, ct),
-            InvoiceDate = DateTime.UtcNow,
-            CustomerId = request.CustomerId,
-            WarehouseId = request.WarehouseId,
-            InvoiceType = request.InvoiceType,
-            Status = SalesInvoiceStatus.Draft,
-            CreatedBy = _currentUser.AuditUserId,
-            CreatedAt = DateTime.UtcNow
-        };
-        invoice.CustomerSnapshotName = await _customers.Query().Where(x => x.CustomerId == request.CustomerId).Select(x => x.DisplayName ?? x.Name).FirstAsync(ct);
-        invoice.CustomerSnapshotTaxNo = await _customers.Query().Where(x => x.CustomerId == request.CustomerId).Select(x => x.TaxRegistrationNo).FirstAsync(ct);
-        invoice.Lines = await BuildLinesAsync(request.WarehouseId, request.Lines, ct);
-        Recalculate(invoice);
 
-        await _invoices.AddAsync(invoice, ct);
-        await _uow.SaveChangesAsync(ct);
+        var customerSnapshotName = await _customers.Query().Where(x => x.CustomerId == request.CustomerId).Select(x => x.DisplayName ?? x.Name).FirstAsync(ct);
+        var customerSnapshotTaxNo = await _customers.Query().Where(x => x.CustomerId == request.CustomerId).Select(x => x.TaxRegistrationNo).FirstAsync(ct);
+        var lines = await BuildLinesAsync(request.WarehouseId, request.Lines, ct);
+
+        var invoice = await _uow.ExecuteInTransactionAsync(async token =>
+        {
+            var entity = new SalesInvoice
+            {
+                InvoiceNo = await _numbers.NextAsync(DocumentTypes.SalesInvoice, token),
+                InvoiceDate = DateTime.UtcNow,
+                CustomerId = request.CustomerId,
+                WarehouseId = request.WarehouseId,
+                InvoiceType = request.InvoiceType,
+                Status = SalesInvoiceStatus.Draft,
+                CreatedBy = _currentUser.AuditUserId,
+                CreatedAt = DateTime.UtcNow,
+                CustomerSnapshotName = customerSnapshotName,
+                CustomerSnapshotTaxNo = customerSnapshotTaxNo,
+                Lines = lines
+            };
+            Recalculate(entity);
+            await _invoices.AddAsync(entity, token);
+            return entity;
+        }, ct);
+
         return new ETagged<SalesInvoiceDto>(_mapping.MapInvoice(invoice), invoice.RowVersion);
     }
 
@@ -190,5 +198,5 @@ public sealed class SalesInvoiceService : ISalesInvoiceService
 
     private SalesInvoiceSummaryDto MapSummary(SalesInvoice x) => new(
         x.SalesInvoiceId, x.InvoiceNo, x.InvoiceDate, x.CustomerId, x.CustomerSnapshotName,
-        x.WarehouseId, x.InvoiceType, x.Status, _mapping.MapInvoiceTotals(x), x.CreatedAt);
+        x.WarehouseId, x.InvoiceType, x.Status, _mapping.MapInvoiceTotals(x), x.CreatedAt, x.GlJournalNo);
 }

Backend/ERPCore/Services/SalesMappingService.cs

@@ -33,6 +33,7 @@ public sealed class SalesMappingService : ISalesMappingService
             invoice.SalesInvoiceId, invoice.InvoiceNo, invoice.InvoiceDate, invoice.CustomerId,
             invoice.CustomerSnapshotName, invoice.CustomerSnapshotTaxNo, invoice.WarehouseId,
             invoice.InvoiceType, invoice.Status, invoice.CreatedBy, invoice.CreatedAt, invoice.UpdatedAt,
+            invoice.GlJournalNo, invoice.GlPostedAt,
             MapInvoiceTotals(invoice),
             invoice.Lines.Select(l => new SalesInvoiceLineDto(
                 l.SalesInvoiceLineId, l.ItemId, l.Description, l.Qty, l.FreeQty, l.WarehouseId,

Backend/ERPCore/Services/SalesPostingService.cs

@@ -5,6 +5,7 @@ using ERPCore.Dtos.Sales;
 using ERPCore.Infra.Auth;
 using ERPCore.Infra.UoW;
 using ERPCore.Repositories.Interfaces;
+using ERPCore.Services.Gl;
 using ERPCore.Services.Interfaces;
 using ERPCore.Services.Stock;
 using ERPCore.System.Errors;
@@ -22,6 +23,13 @@ public sealed class SalesPostingService : ISalesPostingService
     private readonly ISalesDomainService _sales;
     private readonly ICurrentUser _currentUser;
     private readonly IUnitOfWork _uow;
+    private readonly IGeneralLedgerService _gl;
+    private readonly string _glAccountsReceivableCode;
+    private readonly string _glSalesRevenueAccountCode;
+    private readonly string _glSalesDiscountAccountCode;
+    private readonly string _glTaxPayableAccountCode;
+    private readonly string _glCogsAccountCode;
+    private readonly string _glInventoryAccountCode;
 
     public SalesPostingService(
         IRepository<SalesInvoice> invoices,
@@ -31,7 +39,9 @@ public sealed class SalesPostingService : ISalesPostingService
         IFifoCostingService fifo,
         ISalesDomainService sales,
         ICurrentUser currentUser,
-        IUnitOfWork uow)
+        IUnitOfWork uow,
+        IGeneralLedgerService gl,
+        IConfiguration configuration)
     {
         _invoices = invoices;
         _slips = slips;
@@ -41,6 +51,15 @@ public sealed class SalesPostingService : ISalesPostingService
         _sales = sales;
         _currentUser = currentUser;
         _uow = uow;
+        _gl = gl;
+        _glAccountsReceivableCode = configuration["SalesInvoice:GlAccountsReceivableCode"] ?? string.Empty;
+        // Same physical accounts Sales Day End credits for slip/bundle revenue — an invoice
+        // just recognizes them immediately on Post instead of waiting for the day's close.
+        _glSalesRevenueAccountCode = configuration["SalesDayEnd:GlSalesRevenueAccountCode"] ?? string.Empty;
+        _glSalesDiscountAccountCode = configuration["SalesDayEnd:GlSalesDiscountAccountCode"] ?? string.Empty;
+        _glTaxPayableAccountCode = configuration["SalesDayEnd:GlTaxPayableAccountCode"] ?? string.Empty;
+        _glCogsAccountCode = configuration["SalesDayEnd:GlCogsAccountCode"] ?? string.Empty;
+        _glInventoryAccountCode = configuration["SalesDayEnd:GlInventoryAccountCode"] ?? string.Empty;
     }
 
     public async Task<SalesInvoicePostingCheckDto> CheckInvoiceAsync(int salesInvoiceId, CancellationToken ct = default)
@@ -143,7 +162,51 @@ public sealed class SalesPostingService : ISalesPostingService
             setUpdated: x => x.UpdatedAt = DateTime.UtcNow,
             sourceDocType: DocumentTypes.SalesInvoice,
             getDocId: x => x.SalesInvoiceId,
-            ct: ct);
+            ct: ct,
+            afterConsumption: PostInvoiceRevenueAsync);
+
+    /// <summary>
+    /// Revenue recognition for an invoice, run inside the same transaction as its stock
+    /// consumption (so a GL rejection rolls back the posting too, not just leaves it
+    /// half-done): Debit Accounts Receivable for the full NetPayable, Credit Sales Revenue
+    /// (net of discount) and Output Tax, and Debit COGS / Credit Inventory for whatever the
+    /// consumption loop above just cost. Unlike SalesSlip/BundleSale, an invoice is not a
+    /// cashier document and never goes through Sales Day End, so this is its only GL entry.
+    /// </summary>
+    private async Task PostInvoiceRevenueAsync(SalesInvoice invoice, decimal cogs, CancellationToken ct)
+    {
+        if (invoice.NetPayable <= 0 && cogs <= 0) return;
+
+        var now = DateTime.UtcNow;
+        var period = await _gl.GetPeriodByDateAsync(DateOnly.FromDateTime(now), ct);
+        var lines = new List<GlJournalEntryLineRequest>();
+        if (invoice.NetPayable > 0)
+        {
+            lines.Add(new GlJournalEntryLineRequest(_glAccountsReceivableCode, invoice.NetPayable, 0m, $"Invoice {invoice.InvoiceNo}"));
+            if (invoice.DiscountTotal > 0)
+                lines.Add(new GlJournalEntryLineRequest(_glSalesDiscountAccountCode, invoice.DiscountTotal, 0m, "Sales discount"));
+            lines.Add(new GlJournalEntryLineRequest(_glSalesRevenueAccountCode, 0m, invoice.Subtotal, "Sales revenue"));
+            if (invoice.TaxTotal > 0)
+                lines.Add(new GlJournalEntryLineRequest(_glTaxPayableAccountCode, 0m, invoice.TaxTotal, "Output tax payable"));
+        }
+        if (cogs > 0)
+        {
+            lines.Add(new GlJournalEntryLineRequest(_glCogsAccountCode, cogs, 0m, "Cost of goods sold"));
+            lines.Add(new GlJournalEntryLineRequest(_glInventoryAccountCode, 0m, cogs, "Inventory reduction"));
+        }
+
+        var result = await _gl.PostJournalEntryAsync(new GlJournalEntryRequest
+        {
+            PeriodId = period.PeriodId,
+            EntryDate = DateOnly.FromDateTime(now),
+            SourceModule = "SALES_INVOICE",
+            Reference = invoice.InvoiceNo,
+            Narration = $"Sales invoice {invoice.InvoiceNo} posted",
+            Lines = lines
+        }, ct);
+        invoice.GlJournalNo = result.JournalNo;
+        invoice.GlPostedAt = now;
+    }
 
     public Task PostSlipAsync(int salesSlipId, CancellationToken ct = default)
         => PostAsync(
@@ -181,7 +244,11 @@ public sealed class SalesPostingService : ISalesPostingService
         Action<T> setUpdated,
         string sourceDocType,
         Func<T, int> getDocId,
-        CancellationToken ct)
+        CancellationToken ct,
+        /// <summary>Run inside the same transaction, after consumption and status flip, with the
+        /// total COGS this call just consumed — the invoice-only revenue-recognition hook.
+        /// Null for slip/bundle posting, which stays GL-silent here (Sales Day End handles them).</summary>
+        Func<T, decimal, CancellationToken, Task>? afterConsumption = null)
         where T : class
     {
         var doc = await load() ?? throw new NotFoundException(notFoundMessage);
@@ -192,6 +259,7 @@ public sealed class SalesPostingService : ISalesPostingService
 
         await _uow.ExecuteInTransactionAsync(async token =>
         {
+            var totalCogs = 0m;
             foreach (var line in getLines(doc))
             {
                 if (line.Qty <= 0) continue;
@@ -202,12 +270,15 @@ public sealed class SalesPostingService : ISalesPostingService
                 // carry no unit of their own — so this is the quantity FIFO consumes verbatim.
                 var consumed = await _fifo.ConsumeAsync(line.ItemId, line.WarehouseId, null, line.Qty, token);
                 var cost = consumed.Count == 0 ? 0m : consumed.Sum(x => x.Qty * x.UnitCost) / consumed.Sum(x => x.Qty);
+                totalCogs += cost * line.Qty;
                 await _fifo.PostLedgerAsync(line.ItemId, line.WarehouseId, null, null, null, _currentUser.AuditUserId,
                     Direction.Out, line.Qty, cost, 0m, sourceDocType, getDocId(doc), DateTime.UtcNow, token);
             }
 
             setPosted(doc);
             setUpdated(doc);
+
+            if (afterConsumption is not null) await afterConsumption(doc, totalCogs, token);
         }, ct);
     }
 

Backend/ERPCore/Services/SalesReturnService.cs

@@ -6,6 +6,7 @@ using ERPCore.Dtos.Sales;
 using ERPCore.Infra.Auth;
 using ERPCore.Infra.UoW;
 using ERPCore.Repositories.Interfaces;
+using ERPCore.Services.Gl;
 using ERPCore.Services.Interfaces;
 using ERPCore.System.Errors;
 using Microsoft.EntityFrameworkCore;
@@ -17,7 +18,10 @@ namespace ERPCore.Services;
 /// generates an inbound stock movement via the shared <see cref="IStockMutator"/>
 /// (positive delta — creates an inbound FIFO layer at last cost). Single UoW
 /// transaction, mirroring <see cref="PurchaseReturnService"/> with the direction
-/// reversed.
+/// reversed. Also posts a real GL journal entry reversing Inventory/COGS for the
+/// stock movement's value (see <see cref="SalesReturn.GlJournalNo"/> for why revenue/tax
+/// aren't part of it) — reuses the Sales Day End accounts since that's the module
+/// whose COGS this reverses.
 /// </summary>
 public sealed class SalesReturnService : ISalesReturnService
 {
@@ -33,12 +37,16 @@ public sealed class SalesReturnService : ISalesReturnService
     private readonly INumberSequenceService _numbers;
     private readonly ICurrentUser _currentUser;
     private readonly IUnitOfWork _uow;
+    private readonly IGeneralLedgerService _gl;
+    private readonly string _glInventoryAccountCode;
+    private readonly string _glCogsAccountCode;
 
     public SalesReturnService(
         IRepository<SalesReturn> returns, IRepository<Customer> customers, IRepository<Warehouse> warehouses,
         IRepository<Item> items, IRepository<ReasonCode> reasonCodes, IRepository<SalesInvoiceLine> salesInvoiceLines,
         IRepository<SalesReturnLine> returnLines, IRepository<StockLedger> ledger, IStockMutator mutator,
-        INumberSequenceService numbers, ICurrentUser currentUser, IUnitOfWork uow)
+        INumberSequenceService numbers, ICurrentUser currentUser, IUnitOfWork uow,
+        IGeneralLedgerService gl, IConfiguration configuration)
     {
         _returns = returns;
         _customers = customers;
@@ -52,6 +60,9 @@ public sealed class SalesReturnService : ISalesReturnService
         _numbers = numbers;
         _currentUser = currentUser;
         _uow = uow;
+        _gl = gl;
+        _glInventoryAccountCode = configuration["SalesDayEnd:GlInventoryAccountCode"] ?? string.Empty;
+        _glCogsAccountCode = configuration["SalesDayEnd:GlCogsAccountCode"] ?? string.Empty;
     }
 
     public async Task<PagedResponse<SalesReturnSummaryDto>> ListAsync(
@@ -72,7 +83,7 @@ public sealed class SalesReturnService : ISalesReturnService
             .Skip(query.Skip).Take(query.PageSize)
             .Select(r => new SalesReturnSummaryDto(
                 r.ReturnId, r.DocNo, r.CustomerId, r.WarehouseId, r.ReasonCodeId, r.Status,
-                r.CreatedBy, r.CreatedAt, r.Lines.Count, r.Lines.Sum(l => l.Qty)))
+                r.CreatedBy, r.CreatedAt, r.Lines.Count, r.Lines.Sum(l => l.Qty), r.GlJournalNo))
             .ToListAsync(ct);
 
         return PagedResponse<SalesReturnSummaryDto>.Create(rows, query.Page, query.PageSize, total);
@@ -164,6 +175,28 @@ public sealed class SalesReturnService : ISalesReturnService
             await _uow.SaveChangesAsync(token); // flush for a valid ledger sourceDocId
 
             var refs = await _mutator.ApplyAsync(request.WarehouseId, DocumentTypes.SalesReturn, ret.ReturnId, now, deltas, token);
+
+            var totalValue = refs.Sum(r => r.Value);
+            if (totalValue > 0)
+            {
+                var period = await _gl.GetPeriodByDateAsync(DateOnly.FromDateTime(now), token);
+                var glResult = await _gl.PostJournalEntryAsync(new GlJournalEntryRequest
+                {
+                    PeriodId = period.PeriodId,
+                    EntryDate = DateOnly.FromDateTime(now),
+                    SourceModule = "SALES-RETURN",
+                    Reference = docNo,
+                    Narration = $"Sales return {docNo} — stock restocked",
+                    Lines = new List<GlJournalEntryLineRequest>
+                    {
+                        new(_glInventoryAccountCode, totalValue, 0m, $"Sales return {docNo}"),
+                        new(_glCogsAccountCode, 0m, totalValue, $"Sales return {docNo} — COGS reversal")
+                    }
+                }, token);
+                ret.GlJournalNo = glResult.JournalNo;
+                ret.GlPostedAt = now;
+            }
+
             return (ret, refs);
         }, ct);
 
@@ -194,6 +227,7 @@ public sealed class SalesReturnService : ISalesReturnService
 
     private static SalesReturnDto ToDto(SalesReturn r, IReadOnlyList<int> ledgerRefs) => new(
         r.ReturnId, r.DocNo, r.CustomerId, r.WarehouseId, r.ReasonCodeId, r.Status, r.CreatedBy, r.CreatedAt,
+        r.GlJournalNo, r.GlPostedAt,
         r.Lines.OrderBy(l => l.ReturnLineId)
             .Select(l => new SalesReturnLineDto(l.ReturnLineId, l.SalesInvoiceLineId, l.ItemId, l.Qty)).ToList(),
         ledgerRefs);

Backend/ERPCore/Services/SalesSlipService.cs

@@ -17,6 +17,7 @@ namespace ERPCore.Services;
 public sealed class SalesSlipService : ISalesSlipService
 {
     private readonly IRepository<SalesSlip> _slips;
+    private readonly IRepository<SalesDayEnd> _dayEnds;
     private readonly IRepository<Customer> _customers;
     private readonly IRepository<Item> _items;
     private readonly IRepository<Uom> _uoms;
@@ -31,12 +32,13 @@ public sealed class SalesSlipService : ISalesSlipService
     private readonly IUnitOfWork _uow;
 
     public SalesSlipService(
-        IRepository<SalesSlip> slips, IRepository<Customer> customers, IRepository<Item> items,
+        IRepository<SalesSlip> slips, IRepository<SalesDayEnd> dayEnds, IRepository<Customer> customers, IRepository<Item> items,
         IRepository<Uom> uoms, IRepository<Warehouse> warehouses, IRepository<User> users, ISalesDomainService sales, ISalesPostingService posting, ISalesMappingService mapping,
         ISalesDocumentWorkflowService workflow,
         ICurrentUser currentUser, INumberSequenceService numbers, IUnitOfWork uow)
     {
         _slips = slips;
+        _dayEnds = dayEnds;
         _customers = customers;
         _items = items;
         _uoms = uoms;
@@ -107,22 +109,37 @@ public sealed class SalesSlipService : ISalesSlipService
     {
         await _sales.ValidateSalesHeaderAsync(request.CustomerId, request.WarehouseId, request.CashierUserId, true, ct);
 
-        var slip = new SalesSlip
-        {
-            SlipNo = await _numbers.NextAsync(DocumentTypes.SalesSlip, ct),
-            SlipDate = DateTime.UtcNow,
-            CustomerId = request.CustomerId,
-            WarehouseId = request.WarehouseId,
-            CashierUserId = request.CashierUserId,
-            Status = SalesSlipStatus.Draft,
-            CreatedAt = DateTime.UtcNow
-        };
-        slip.CustomerSnapshotName = await _customers.Query().Where(x => x.CustomerId == request.CustomerId).Select(x => x.DisplayName ?? x.Name).FirstAsync(ct);
-        slip.Lines = await BuildLinesAsync(request.WarehouseId, request.Lines, ct);
-        Recalculate(slip);
+        // A cashier can't ring up more sales for a business date they've already closed
+        // (SalesDayEndService.CloseAsync) — otherwise the new slip would sit outside every
+        // day-end's totals and GL posting forever (docs/14 Sales Day End).
+        var today = DateOnly.FromDateTime(DateTime.UtcNow);
+        var alreadyClosed = await _dayEnds.Query().AsNoTracking()
+            .AnyAsync(x => x.CashierUserId == request.CashierUserId && x.BusinessDate == today, ct);
+        if (alreadyClosed)
+            throw new ConflictException($"Cashier {request.CashierUserId} already closed today's ({today:yyyy-MM-dd}) sales — day-end has been posted.");
+
+        var customerSnapshotName = await _customers.Query().Where(x => x.CustomerId == request.CustomerId).Select(x => x.DisplayName ?? x.Name).FirstAsync(ct);
+        var lines = await BuildLinesAsync(request.WarehouseId, request.Lines, ct);
+
+        var slip = await _uow.ExecuteInTransactionAsync(async token =>
+        {
+            var entity = new SalesSlip
+            {
+                SlipNo = await _numbers.NextAsync(DocumentTypes.SalesSlip, token),
+                SlipDate = DateTime.UtcNow,
+                CustomerId = request.CustomerId,
+                WarehouseId = request.WarehouseId,
+                CashierUserId = request.CashierUserId,
+                CustomerSnapshotName = customerSnapshotName,
+                Status = SalesSlipStatus.Draft,
+                CreatedAt = DateTime.UtcNow,
+                Lines = lines
+            };
+            Recalculate(entity);
+            await _slips.AddAsync(entity, token);
+            return entity;
+        }, ct);
 
-        await _slips.AddAsync(slip, ct);
-        await _uow.SaveChangesAsync(ct);
         return new ETagged<SalesSlipDto>(_mapping.MapSlip(slip), slip.RowVersion);
     }
 

Backend/ERPCore/Services/TransferService.cs

@@ -17,6 +17,14 @@ namespace ERPCore.Services;
 /// layers (row-locked; negative-stock blocked) and records the value-weighted cost
 /// on the line; receive recreates the destination layer at that cost
 /// (cost-preserving — no revaluation). Both run in a single UoW transaction.
+///
+/// Deliberately posts no GL journal entry: <see cref="Warehouse"/> carries no GL
+/// account of its own (unlike a GL "location"/cost-center dimension), so every
+/// warehouse's stock sits in the same Inventory account — a transfer would debit and
+/// credit that identical account for the identical amount, a no-op journal entry that
+/// exists only to say nothing. The per-warehouse movement is still fully recorded in
+/// <see cref="StockLedger"/>/<see cref="StockLayer"/>, which is what On-Hand-by-warehouse
+/// reporting actually reads from.
 /// </summary>
 public sealed class TransferService : ITransferService
 {

Backend/ERPCore/System/Errors/ErrorCodes.cs

@@ -77,4 +77,9 @@ public static class ErrorCodes
     public const string GrnNotPayable = "GRN_NOT_PAYABLE";
     public const string GrnPaymentExceedsBalance = "GRN_PAYMENT_EXCEEDS_BALANCE";
     public const string GrnBankAccountNotFound = "GRN_BANK_ACCOUNT_NOT_FOUND";
+
+    // Sales invoice payments
+    public const string SalesInvoiceNotPayable = "SALES_INVOICE_NOT_PAYABLE";
+    public const string SalesInvoicePaymentExceedsBalance = "SALES_INVOICE_PAYMENT_EXCEEDS_BALANCE";
+    public const string SalesInvoiceBankAccountNotFound = "SALES_INVOICE_BANK_ACCOUNT_NOT_FOUND";
 }

Backend/ERPCore/appsettings.json

@@ -31,5 +31,21 @@
     "GlVatRecoverableAccountCode": "1200",
     "GlClearingAccountCode": "2000"
   },
+  "SalesDayEnd": {
+    "GlCashAccountCode": "1000-01",
+    "GlSalesRevenueAccountCode": "4000",
+    "GlSalesDiscountAccountCode": "4100",
+    "GlTaxPayableAccountCode": "2100",
+    "GlCogsAccountCode": "5000",
+    "GlInventoryAccountCode": "1100"
+  },
+  "Adjustment": {
+    "GlInventoryAccountCode": "1100",
+    "GlGainAccountCode": "4200",
+    "GlLossAccountCode": "5100"
+  },
+  "SalesInvoice": {
+    "GlAccountsReceivableCode": "1300"
+  },
   "AllowedHosts": "*"
 }