diff --git a/Frontend/erp-system/app/dashboard/sales/bundles/[id]/page.tsx b/Frontend/erp-system/app/dashboard/sales/bundles/[id]/page.tsx
index 28c302c..b2e534b 100644
--- a/Frontend/erp-system/app/dashboard/sales/bundles/[id]/page.tsx
+++ b/Frontend/erp-system/app/dashboard/sales/bundles/[id]/page.tsx
@@ -15,7 +15,9 @@ import { Input } from "@/components/ui/input"
 import { Label } from "@/components/ui/label"
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select"
 import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table"
+import { formatUomName } from "@/lib/format-uom"
 import { cn } from "@/lib/utils"
+import { validateBundleSale } from "@/lib/sales-validation"
 import { BundleSale, BundleSaleTemplateSummary, BundleSaleTemplateLine, UpdateBundleSaleRequest } from "@/types/bundles"
 import { customersApi } from "@/lib/api/customers"
 import { warehousesApi } from "@/lib/api/warehouses"
@@ -138,7 +140,20 @@ export default function BundleSaleDetailPage() {
   }
 
   async function saveBundle() {
-    if (!bundle || !customerId || !warehouseId || !cashierUserId || !templateId) return
+    if (!bundle) return
+    const validationError = validateBundleSale({
+      customerId,
+      warehouseId,
+      cashierUserId,
+      templateId,
+      bundleName,
+      bundlePrice,
+      lines,
+    })
+    if (validationError) {
+      setError(validationError)
+      return
+    }
     setBusy(true)
     setError(null)
     try {
@@ -393,7 +408,7 @@ export default function BundleSaleDetailPage() {
                         <SelectContent>
                           {uoms.map((uom) => (
                             <SelectItem key={uom.uomId} value={String(uom.uomId)}>
-                              {uom.name}
+                              {formatUomName(uom.name)}
                             </SelectItem>
                           ))}
                         </SelectContent>
diff --git a/Frontend/erp-system/app/dashboard/sales/bundles/new/page.tsx b/Frontend/erp-system/app/dashboard/sales/bundles/new/page.tsx
index ce49664..655d326 100644
--- a/Frontend/erp-system/app/dashboard/sales/bundles/new/page.tsx
+++ b/Frontend/erp-system/app/dashboard/sales/bundles/new/page.tsx
@@ -18,8 +18,10 @@ import { Label } from "@/components/ui/label"
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select"
 import { Skeleton } from "@/components/ui/skeleton"
 import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table"
+import { formatUomName } from "@/lib/format-uom"
 import { cn } from "@/lib/utils"
 import { toast } from "@/components/ui/toast"
+import { validateBundleSale } from "@/lib/sales-validation"
 import { Customer } from "@/types/customers"
 import { ItemListItem, Uom, Warehouse } from "@/types/master-data"
 import { ManagedUser } from "@/types/users"
@@ -54,7 +56,7 @@ function NewBundleSaleContent() {
   const [warehouseId, setWarehouseId] = useState<number | null>(null)
   const [cashierUserId, setCashierUserId] = useState<number | null>(null)
   const [templateId, setTemplateId] = useState<number | null>(templateFromQuery ? Number(templateFromQuery) : null)
-  const [bundleName, setBundleName] = useState("Demo Bundle")
+  const [bundleName, setBundleName] = useState("")
   const [bundlePrice, setBundlePrice] = useState<number>(0)
   const [allowPriceOverride, setAllowPriceOverride] = useState(false)
   const [lines, setLines] = useState<EditableLine[]>([])
@@ -78,10 +80,10 @@ function NewBundleSaleContent() {
         setWarehouses(whRes.items)
         setUsers(userRes.items)
         setTemplates(templateRes.items)
-        setCustomerId(cust.items[0]?.customerId ?? null)
-        setWarehouseId(whRes.items[0]?.warehouseId ?? null)
-        setCashierUserId(userRes.items[0]?.userId ?? null)
-        setTemplateId((current) => current ?? templateRes.items[0]?.bundleSaleTemplateId ?? null)
+        setCustomerId(null)
+        setWarehouseId(null)
+        setCashierUserId(null)
+        setTemplateId((current) => current ?? null)
       })
       .catch((err) => setSubmitError(errorMessage(err)))
       .finally(() => setLoading(false))
@@ -122,12 +124,21 @@ function NewBundleSaleContent() {
   }
 
   async function submit() {
-    if (!customerId || !warehouseId || !cashierUserId || !templateId || !template) {
-      setSubmitError("Select customer, warehouse, cashier, and bundle template.")
+    const validationError = validateBundleSale({
+      customerId,
+      warehouseId,
+      cashierUserId,
+      templateId,
+      bundleName,
+      bundlePrice,
+      lines,
+    })
+    if (validationError) {
+      setSubmitError(validationError)
       return
     }
-    if (lines.length === 0) {
-      setSubmitError("Add at least one bundle component line.")
+    if (!template) {
+      setSubmitError("Load a bundle template before saving.")
       return
     }
     setSaving(true)
@@ -189,28 +200,28 @@ function NewBundleSaleContent() {
         <div className="grid gap-4 sm:grid-cols-2 lg:grid-cols-3">
           <div className="space-y-1.5">
             <Label>Customer</Label>
-            <Select value={customerId ? String(customerId) : "all"} onValueChange={(v) => setCustomerId(v === "all" ? null : Number(v))}>
+            <Select value={customerId ? String(customerId) : ""} onValueChange={(v) => setCustomerId(v ? Number(v) : null)}>
               <SelectTrigger><SelectValue placeholder="Select customer" /></SelectTrigger>
               <SelectContent>{customers.map((c) => <SelectItem key={c.customerId} value={String(c.customerId)}>{c.customerCode} - {c.displayName ?? c.name}</SelectItem>)}</SelectContent>
             </Select>
           </div>
           <div className="space-y-1.5">
             <Label>Warehouse</Label>
-            <Select value={warehouseId ? String(warehouseId) : "all"} onValueChange={(v) => setWarehouseId(v === "all" ? null : Number(v))}>
+            <Select value={warehouseId ? String(warehouseId) : ""} onValueChange={(v) => setWarehouseId(v ? Number(v) : null)}>
               <SelectTrigger><SelectValue placeholder="Select warehouse" /></SelectTrigger>
               <SelectContent>{warehouses.map((w) => <SelectItem key={w.warehouseId} value={String(w.warehouseId)}>{w.code} - {w.name}</SelectItem>)}</SelectContent>
             </Select>
           </div>
           <div className="space-y-1.5">
             <Label>Cashier</Label>
-            <Select value={cashierUserId ? String(cashierUserId) : "all"} onValueChange={(v) => setCashierUserId(v === "all" ? null : Number(v))}>
+            <Select value={cashierUserId ? String(cashierUserId) : ""} onValueChange={(v) => setCashierUserId(v ? Number(v) : null)}>
               <SelectTrigger><SelectValue placeholder="Select cashier" /></SelectTrigger>
               <SelectContent>{users.map((u) => <SelectItem key={u.userId} value={String(u.userId)}>{u.displayName}</SelectItem>)}</SelectContent>
             </Select>
           </div>
           <div className="space-y-1.5">
             <Label>Template</Label>
-            <Select value={templateId ? String(templateId) : "all"} onValueChange={(v) => setTemplateId(v === "all" ? null : Number(v))}>
+            <Select value={templateId ? String(templateId) : ""} onValueChange={(v) => setTemplateId(v ? Number(v) : null)}>
               <SelectTrigger><SelectValue placeholder={templateLabel} /></SelectTrigger>
               <SelectContent>{templates.map((t) => <SelectItem key={t.bundleSaleTemplateId} value={String(t.bundleSaleTemplateId)}>{t.templateCode} - {t.templateName}</SelectItem>)}</SelectContent>
             </Select>
@@ -256,7 +267,7 @@ function NewBundleSaleContent() {
               {lines.map((line) => (
                 <TableRow key={line.key}>
                   <TableCell className="min-w-72">
-                    <Select value={line.itemId ? String(line.itemId) : "all"} onValueChange={(v) => {
+                    <Select value={line.itemId ? String(line.itemId) : ""} onValueChange={(v) => {
                         const itemId = Number(v)
                         const item = items.find((candidate) => candidate.itemId === itemId)
                         updateLine(line.key, {
@@ -278,14 +289,14 @@ function NewBundleSaleContent() {
                     </Select>
                   </TableCell>
                   <TableCell className="min-w-40">
-                      <Select value={line.uomId ? String(line.uomId) : "all"} onValueChange={(v) => updateLine(line.key, { uomId: v === "all" ? 0 : Number(v) })} disabled>
+                      <Select value={line.uomId ? String(line.uomId) : ""} onValueChange={(v) => updateLine(line.key, { uomId: v ? Number(v) : 0 })} disabled>
                       <SelectTrigger className="h-9 text-sm">
                         <SelectValue placeholder="Select UOM" />
                       </SelectTrigger>
                       <SelectContent>
                         {uoms.map((uom) => (
                           <SelectItem key={uom.uomId} value={String(uom.uomId)}>
-                            {uom.name}
+                            {formatUomName(uom.name)}
                           </SelectItem>
                         ))}
                       </SelectContent>
diff --git a/Frontend/erp-system/app/dashboard/sales/bundles/page.tsx b/Frontend/erp-system/app/dashboard/sales/bundles/page.tsx
index 5d84432..3fbcf36 100644
--- a/Frontend/erp-system/app/dashboard/sales/bundles/page.tsx
+++ b/Frontend/erp-system/app/dashboard/sales/bundles/page.tsx
@@ -2,7 +2,7 @@
 
 import { useEffect, useMemo, useState } from "react"
 import Link from "next/link"
-import { ChevronLeft, ChevronRight, Eye, Filter, FileText, Plus, Printer } from "lucide-react"
+import { ChevronLeft, ChevronRight, Eye, FileText, Plus, Printer, Search } from "lucide-react"
 
 import { bundleApi } from "@/lib/api/bundles"
 import { customersApi } from "@/lib/api/customers"
@@ -10,6 +10,7 @@ import { warehousesApi } from "@/lib/api/warehouses"
 import { errorMessage } from "@/lib/error-map"
 import { Button, buttonVariants } from "@/components/ui/button"
 import { Badge } from "@/components/ui/badge"
+import { Card, CardContent, CardHeader } from "@/components/ui/card"
 import { Input } from "@/components/ui/input"
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select"
 import { Skeleton } from "@/components/ui/skeleton"
@@ -23,7 +24,6 @@ import { cn } from "@/lib/utils"
 type StatusFilter = BundleSaleStatus | "All"
 
 const PAGE_SIZE = 10
-const tabs = ["All", "Draft", "Posted", "Cancelled"] as const
 
 function statusClass(status: BundleSaleStatus) {
   switch (status) {
@@ -46,7 +46,6 @@ export default function BundleSalesPage() {
   const [searchInput, setSearchInput] = useState("")
   const [query, setQuery] = useState("")
   const [page, setPage] = useState(1)
-  const [showFilters, setShowFilters] = useState(false)
   const [customers, setCustomers] = useState<Customer[]>([])
   const [warehouses, setWarehouses] = useState<Warehouse[]>([])
 
@@ -119,88 +118,74 @@ export default function BundleSalesPage() {
         </div>
       </div>
 
-      <div className="rounded-2xl border bg-card shadow-sm">
-        <div className="flex flex-col gap-3 border-b px-4 py-4 lg:flex-row lg:items-center">
-          <div className="flex flex-wrap gap-2">
-            {tabs.map((t) => (
-              <button
-                key={t}
-                onClick={() => setStatus(t)}
-                className={cn(
-                  "rounded-full border px-3 py-1.5 text-xs font-medium transition-colors",
-                  status === t ? "border-primary bg-primary text-primary-foreground" : "border-border text-muted-foreground hover:text-foreground"
-                )}
-              >
-                {t}
-              </button>
-            ))}
+      <Card>
+        <CardHeader className="border-b">
+          <div className="grid gap-3 sm:grid-cols-2 xl:grid-cols-5">
+            <div className="relative sm:col-span-2 xl:col-span-2">
+              <Search className="pointer-events-none absolute top-1/2 left-4 size-5 -translate-y-1/2 text-muted-foreground" />
+              <Input
+                value={searchInput}
+                onChange={(e) => setSearchInput(e.target.value)}
+                placeholder="Search bundle, code, or customer"
+                className="h-14 w-full pl-11 text-base"
+                aria-label="Search bundles"
+              />
+            </div>
+            <Select<StatusFilter> value={status} onValueChange={(v) => setStatus(v ?? "All")}>
+              <SelectTrigger className="h-14! w-full text-base">
+                <SelectValue placeholder="All statuses" />
+              </SelectTrigger>
+              <SelectContent>
+                <SelectItem value="All" className="text-base">All statuses</SelectItem>
+                <SelectItem value="Draft" className="text-base">Draft</SelectItem>
+                <SelectItem value="Posted" className="text-base">Posted</SelectItem>
+                <SelectItem value="Cancelled" className="text-base">Cancelled</SelectItem>
+              </SelectContent>
+            </Select>
+            <Select value={customerId ? String(customerId) : "all"} onValueChange={(v) => setCustomerId(v === "all" ? null : Number(v))}>
+              <SelectTrigger className="h-14! w-full text-base">
+                <SelectValue placeholder="All customers" />
+              </SelectTrigger>
+              <SelectContent>
+                <SelectItem value="all" className="text-base">All customers</SelectItem>
+                {customers.map((c) => (
+                  <SelectItem key={c.customerId} value={String(c.customerId)} className="text-base">
+                    {c.customerCode} - {c.displayName ?? c.name}
+                  </SelectItem>
+                ))}
+              </SelectContent>
+            </Select>
+            <Select value={warehouseId ? String(warehouseId) : "all"} onValueChange={(v) => setWarehouseId(v === "all" ? null : Number(v))}>
+              <SelectTrigger className="h-14! w-full text-base">
+                <SelectValue placeholder="All warehouses" />
+              </SelectTrigger>
+              <SelectContent>
+                <SelectItem value="all" className="text-base">All warehouses</SelectItem>
+                {warehouses.map((w) => (
+                  <SelectItem key={w.warehouseId} value={String(w.warehouseId)} className="text-base">
+                    {w.code} - {w.name}
+                  </SelectItem>
+                ))}
+              </SelectContent>
+            </Select>
           </div>
-          <div className="flex flex-1 flex-col gap-3 lg:flex-row lg:items-center lg:justify-end">
-            <Input
-              value={searchInput}
-              onChange={(e) => setSearchInput(e.target.value)}
-              placeholder="Filter by bundle, code, or customer"
-              className="h-12 w-full lg:max-w-sm"
-            />
-            <Button variant="outline" size="sm" className="lg:ml-auto" onClick={() => setShowFilters((v) => !v)}>
-              <Filter className="size-4" />
-              Advanced
+          <div className="flex justify-end">
+            <Button
+              type="button"
+              variant="outline"
+              size="sm"
+              onClick={() => {
+                setCustomerId(null)
+                setWarehouseId(null)
+                setStatus("All")
+                setSearchInput("")
+                setQuery("")
+              }}
+            >
+              Reset filters
             </Button>
           </div>
-        </div>
-
-        {showFilters && (
-          <div className="grid gap-4 border-b px-4 py-4 md:grid-cols-3">
-            <div className="space-y-1.5">
-              <div className="text-xs font-medium text-muted-foreground">Customer</div>
-              <Select value={customerId ? String(customerId) : "all"} onValueChange={(v) => setCustomerId(v === "all" ? null : Number(v))}>
-                <SelectTrigger className="h-10">
-                  <SelectValue placeholder="All customers" />
-                </SelectTrigger>
-                <SelectContent>
-                  <SelectItem value="all">All customers</SelectItem>
-                  {customers.map((c) => (
-                    <SelectItem key={c.customerId} value={String(c.customerId)}>
-                      {c.customerCode} - {c.displayName ?? c.name}
-                    </SelectItem>
-                  ))}
-                </SelectContent>
-              </Select>
-            </div>
-            <div className="space-y-1.5">
-              <div className="text-xs font-medium text-muted-foreground">Warehouse</div>
-              <Select value={warehouseId ? String(warehouseId) : "all"} onValueChange={(v) => setWarehouseId(v === "all" ? null : Number(v))}>
-                <SelectTrigger className="h-10">
-                  <SelectValue placeholder="All warehouses" />
-                </SelectTrigger>
-                <SelectContent>
-                  <SelectItem value="all">All warehouses</SelectItem>
-                  {warehouses.map((w) => (
-                    <SelectItem key={w.warehouseId} value={String(w.warehouseId)}>
-                      {w.code} - {w.name}
-                    </SelectItem>
-                  ))}
-                </SelectContent>
-              </Select>
-            </div>
-            <div className="flex items-end gap-2">
-              <Button
-                type="button"
-                variant="outline"
-                className="flex-1"
-                onClick={() => {
-                  setCustomerId(null)
-                  setWarehouseId(null)
-                  setStatus("All")
-                  setSearchInput("")
-                  setQuery("")
-                }}
-              >
-                Reset
-              </Button>
-            </div>
-          </div>
-        )}
+        </CardHeader>
 
         {error && <div className="mx-4 mt-4 rounded-lg border border-destructive/30 bg-destructive/5 p-5 text-base text-destructive">{error}</div>}
 
@@ -221,6 +206,7 @@ export default function BundleSalesPage() {
 
         {!error && rows !== null && visibleRows.length > 0 && (
           <>
+            <CardContent className="px-0">
             <div className="overflow-x-auto">
               <Table className="text-base">
                 <TableHeader>
@@ -266,6 +252,7 @@ export default function BundleSalesPage() {
                 </TableBody>
               </Table>
             </div>
+            </CardContent>
 
             <div className="border-t px-4 py-3">
               <div className="grid gap-3 text-sm md:grid-cols-2">
@@ -302,7 +289,7 @@ export default function BundleSalesPage() {
             )}
           </>
         )}
-      </div>
+      </Card>
     </div>
   )
 }
diff --git a/Frontend/erp-system/app/dashboard/sales/free-issues/new/page.tsx b/Frontend/erp-system/app/dashboard/sales/free-issues/new/page.tsx
index 2dced6d..5e37842 100644
--- a/Frontend/erp-system/app/dashboard/sales/free-issues/new/page.tsx
+++ b/Frontend/erp-system/app/dashboard/sales/free-issues/new/page.tsx
@@ -6,9 +6,12 @@ import { ArrowLeft, Pencil, Plus, Save, Trash2, X } from "lucide-react"
 
 import { Button, buttonVariants } from "@/components/ui/button"
 import { Input } from "@/components/ui/input"
+import { Label } from "@/components/ui/label"
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select"
 import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table"
+import { formatUomName } from "@/lib/format-uom"
 import { cn } from "@/lib/utils"
+import { validateSalesDocument } from "@/lib/sales-validation"
 import { errorMessage } from "@/lib/error-map"
 import { salesApi } from "@/lib/api/sales"
 import { customersApi } from "@/lib/api/customers"
@@ -88,7 +91,7 @@ export default function NewFreeIssuePage() {
           warehouseName: warehouse?.name ?? `Warehouse ${detail.data.warehouseId}`,
           itemName: item?.name ?? firstLine?.description ?? "—",
           itemSku: item?.sku ?? `SKU-${firstLine?.itemId ?? 0}`,
-          uomName: uom?.name ?? `UOM ${firstLine?.uomId ?? 0}`,
+          uomName: uom?.name ? formatUomName(uom.name) : `UOM ${firstLine?.uomId ?? 0}`,
           qty: firstLine?.qty ?? 0,
           freeQty: firstLine?.freeQty ?? 0,
         } satisfies FreeIssueRow
@@ -111,17 +114,10 @@ export default function NewFreeIssuePage() {
         setUoms(uomRes.items)
         setWarehouses(whRes.items)
         setUsers(userRes.items)
-        setCustomerId(cust.items[0]?.customerId ?? null)
-        setWarehouseId(whRes.items[0]?.warehouseId ?? null)
-        setCashierUserId(userRes.items[0]?.userId ?? null)
-        setLines([
-          {
-            ...blankLine("line-1"),
-            itemId: itemRes.items[0]?.itemId ?? 0,
-            uomId: itemRes.items[0]?.baseUomId ?? uomRes.items[0]?.uomId ?? 0,
-            warehouseId: whRes.items[0]?.warehouseId ?? 0,
-          },
-        ])
+        setCustomerId(null)
+        setWarehouseId(null)
+        setCashierUserId(null)
+        setLines([blankLine("line-1")])
         await refreshRows()
       })
       .catch((err) => setError(errorMessage(err)))
@@ -132,12 +128,18 @@ export default function NewFreeIssuePage() {
     setLines((prev) => prev.map((line) => (line.key === key ? { ...line, ...patch } : line)))
   }
 
+  function updateHeaderWarehouse(nextWarehouseId: number | null) {
+    setWarehouseId(nextWarehouseId)
+    setLines((prev) => prev.map((line) => ({ ...line, warehouseId: nextWarehouseId ?? line.warehouseId })))
+    setEditingLines((prev) => prev.map((line) => ({ ...line, warehouseId: nextWarehouseId ?? line.warehouseId })))
+  }
+
   function updateEditingLine(key: string, patch: Partial<Line>) {
     setEditingLines((prev) => prev.map((line) => (line.key === key ? { ...line, ...patch } : line)))
   }
 
   function addLine() {
-    setLines((prev) => [...prev, blankLine(`line-${Date.now()}`)])
+    setLines((prev) => [...prev, { ...blankLine(`line-${Date.now()}`), warehouseId: warehouseId ?? 0 }])
   }
 
   function removeLine(key: string) {
@@ -146,20 +148,25 @@ export default function NewFreeIssuePage() {
 
   function selectItem(key: string, itemId: number) {
     const item = items.find((candidate) => candidate.itemId === itemId)
-    updateLine(key, { itemId, uomId: item?.baseUomId ?? 0 })
+    updateLine(key, { itemId, uomId: item?.baseUomId ?? 0, warehouseId: warehouseId ?? 0 })
   }
 
   function selectEditingItem(key: string, itemId: number) {
     const item = items.find((candidate) => candidate.itemId === itemId)
-    updateEditingLine(key, { itemId, uomId: item?.baseUomId ?? 0 })
+    updateEditingLine(key, { itemId, uomId: item?.baseUomId ?? 0, warehouseId: warehouseId ?? 0 })
   }
 
   async function submit() {
     const activeLines = editingRowId ? editingLines : lines
-    if (!customerId || !warehouseId || !cashierUserId) return setError("Select customer, warehouse, and cashier.")
-    if (activeLines.some((line) => !line.itemId)) return setError("Select an item for every line.")
-    if (activeLines.some((line) => !line.uomId)) return setError("Select a valid UOM for every line.")
-    if (activeLines.some((line) => !line.warehouseId)) return setError("Select a warehouse for every line.")
+    const validationError = validateSalesDocument({
+      customerId,
+      warehouseId,
+      cashierUserId,
+      requireCashierUser: true,
+      lines: activeLines,
+      lineLabel: "free issue line",
+    })
+    if (validationError) return setError(validationError)
 
     setSaving(true)
     setError(null)
@@ -198,6 +205,11 @@ export default function NewFreeIssuePage() {
         toast.success("Free issue created", created.data.slipNo)
       }
 
+      if (!editingRowId) {
+        setCustomerId(null)
+        setWarehouseId(null)
+        setCashierUserId(null)
+      }
       setLines([blankLine("line-1")])
       await refreshRows()
     } catch (err) {
@@ -281,6 +293,57 @@ export default function NewFreeIssuePage() {
 
       {error ? <div className="rounded-lg border border-destructive/30 bg-destructive/5 p-5 text-base text-destructive">{error}</div> : null}
 
+      <section className="rounded-2xl border border-border bg-card p-4 shadow-[var(--shadow-panel)]">
+        <h2 className="text-sm font-semibold">{editingRowId ? "Free issue header" : "Create free issue header"}</h2>
+        <div className="mt-3 grid gap-4 sm:grid-cols-2 lg:grid-cols-3">
+          <div className="space-y-1.5">
+            <Label className="text-xs">Customer</Label>
+            <Select value={customerId ? String(customerId) : ""} onValueChange={(v) => setCustomerId(v ? Number(v) : null)}>
+              <SelectTrigger className="h-9 text-sm">
+                <SelectValue placeholder="Select customer" />
+              </SelectTrigger>
+              <SelectContent>
+                {customers.map((c) => (
+                  <SelectItem key={c.customerId} value={String(c.customerId)}>
+                    {c.customerCode} - {c.displayName ?? c.name}
+                  </SelectItem>
+                ))}
+              </SelectContent>
+            </Select>
+          </div>
+          <div className="space-y-1.5">
+            <Label className="text-xs">Warehouse</Label>
+            <Select value={warehouseId ? String(warehouseId) : ""} onValueChange={(v) => updateHeaderWarehouse(v ? Number(v) : null)}>
+              <SelectTrigger className="h-9 text-sm">
+                <SelectValue placeholder="Select warehouse" />
+              </SelectTrigger>
+              <SelectContent>
+                {warehouses.map((w) => (
+                  <SelectItem key={w.warehouseId} value={String(w.warehouseId)}>
+                    {w.code} - {w.name}
+                  </SelectItem>
+                ))}
+              </SelectContent>
+            </Select>
+          </div>
+          <div className="space-y-1.5">
+            <Label className="text-xs">Cashier</Label>
+            <Select value={cashierUserId ? String(cashierUserId) : ""} onValueChange={(v) => setCashierUserId(v ? Number(v) : null)}>
+              <SelectTrigger className="h-9 text-sm">
+                <SelectValue placeholder="Select cashier" />
+              </SelectTrigger>
+              <SelectContent>
+                {users.map((u) => (
+                  <SelectItem key={u.userId} value={String(u.userId)}>
+                    {u.displayName}
+                  </SelectItem>
+                ))}
+              </SelectContent>
+            </Select>
+          </div>
+        </div>
+      </section>
+
       {editingRowId ? (
         <section className="rounded-2xl border border-sky-200 bg-sky-50 shadow-[var(--shadow-panel)]">
           <div className="flex items-center justify-between border-b border-sky-200 px-4 py-3">
@@ -327,7 +390,7 @@ export default function NewFreeIssuePage() {
                         <SelectContent>
                           {uoms.map((u) => (
                             <SelectItem key={u.uomId} value={String(u.uomId)}>
-                              {u.name}
+                              {formatUomName(u.name)}
                             </SelectItem>
                           ))}
                         </SelectContent>
@@ -392,7 +455,7 @@ export default function NewFreeIssuePage() {
                         <SelectContent>
                           {uoms.map((u) => (
                             <SelectItem key={u.uomId} value={String(u.uomId)}>
-                              {u.name}
+                              {formatUomName(u.name)}
                             </SelectItem>
                           ))}
                         </SelectContent>
diff --git a/Frontend/erp-system/app/dashboard/sales/invoices/[id]/page.tsx b/Frontend/erp-system/app/dashboard/sales/invoices/[id]/page.tsx
index 94793fb..1f57856 100644
--- a/Frontend/erp-system/app/dashboard/sales/invoices/[id]/page.tsx
+++ b/Frontend/erp-system/app/dashboard/sales/invoices/[id]/page.tsx
@@ -11,8 +11,10 @@ import { itemsApi } from "@/lib/api/items"
 import { uomsApi } from "@/lib/api/uoms"
 import { warehousesApi } from "@/lib/api/warehouses"
 import { errorMessage } from "@/lib/error-map"
+import { findUomLabel, formatUomName } from "@/lib/format-uom"
 import { cn } from "@/lib/utils"
 import { getSuggestedUnitPrice } from "@/lib/sales-line-utils"
+import { validateSalesDocument } from "@/lib/sales-validation"
 import { Customer } from "@/types/customers"
 import { ItemListItem, Uom, Warehouse } from "@/types/master-data"
 import { CreateSalesInvoiceLineRequest, SalesInvoice, SalesInvoicePostingCheck, SalesInvoiceStatus, SalesInvoiceType } from "@/types/sales"
@@ -171,9 +173,15 @@ export default function SalesInvoiceDetailPage({ params }: { params: Promise<{ i
   }
 
   async function save() {
-    if (!customerId || !warehouseId || !etag) return
-    if (lines.some((line) => !line.itemId || !line.uomId || !line.warehouseId)) {
-      setError("Select item, UOM and warehouse for every line.")
+    if (!etag) return
+    const validationError = validateSalesDocument({
+      customerId,
+      warehouseId,
+      lines,
+      lineLabel: "invoice line",
+    })
+    if (validationError) {
+      setError(validationError)
       return
     }
 
@@ -353,7 +361,7 @@ export default function SalesInvoiceDetailPage({ params }: { params: Promise<{ i
                     <div className="font-medium text-foreground">{line.description}</div>
                     <div className="text-xs text-muted-foreground">SKU {items.find((i) => i.itemId === line.itemId)?.sku ?? `#${line.itemId}`}</div>
                   </td>
-                  <td className="px-4 py-3">{uoms.find((u) => u.uomId === line.uomId)?.name ?? `#${line.uomId}`}</td>
+                  <td className="px-4 py-3">{findUomLabel(uoms, line.uomId)}</td>
                   <td className="px-4 py-3 text-right">{line.qty.toFixed(0)}</td>
                   <td className="px-4 py-3 text-right">{line.freeQty > 0 ? line.freeQty.toFixed(0) : "—"}</td>
                   <td className="px-4 py-3 text-right">{money.format(line.unitPrice)}</td>
@@ -505,7 +513,7 @@ export default function SalesInvoiceDetailPage({ params }: { params: Promise<{ i
                             <option value="">UOM</option>
                             {uoms.map((u) => (
                               <option key={u.uomId} value={String(u.uomId)}>
-                                {u.name}
+                                {formatUomName(u.name)}
                               </option>
                             ))}
                           </select>
diff --git a/Frontend/erp-system/app/dashboard/sales/invoices/[id]/print/page.tsx b/Frontend/erp-system/app/dashboard/sales/invoices/[id]/print/page.tsx
index c86302d..f1ef563 100644
--- a/Frontend/erp-system/app/dashboard/sales/invoices/[id]/print/page.tsx
+++ b/Frontend/erp-system/app/dashboard/sales/invoices/[id]/print/page.tsx
@@ -10,6 +10,7 @@ import { itemsApi } from "@/lib/api/items"
 import { uomsApi } from "@/lib/api/uoms"
 import { warehousesApi } from "@/lib/api/warehouses"
 import { errorMessage } from "@/lib/error-map"
+import { findUomLabel } from "@/lib/format-uom"
 import { Button, buttonVariants } from "@/components/ui/button"
 import { Skeleton } from "@/components/ui/skeleton"
 import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table"
@@ -143,7 +144,7 @@ export default function SalesInvoicePrintPage({ params }: { params: { id: string
                     <div className="font-medium text-foreground">{line.description}</div>
                     <div className="text-xs text-muted-foreground">SKU {items.find((i) => i.itemId === line.itemId)?.sku ?? `#${line.itemId}`}</div>
                   </TableCell>
-                  <TableCell>{uoms.find((u) => u.uomId === line.uomId)?.name ?? `#${line.uomId}`}</TableCell>
+                  <TableCell>{findUomLabel(uoms, line.uomId)}</TableCell>
                   <TableCell className="text-right">{line.qty.toFixed(2)}</TableCell>
                   <TableCell className="text-right">{line.freeQty > 0 ? line.freeQty.toFixed(2) : "—"}</TableCell>
                   <TableCell className="text-right">{line.unitPrice.toFixed(2)}</TableCell>
diff --git a/Frontend/erp-system/app/dashboard/sales/invoices/new/page.tsx b/Frontend/erp-system/app/dashboard/sales/invoices/new/page.tsx
index ad3e323..fd667b2 100644
--- a/Frontend/erp-system/app/dashboard/sales/invoices/new/page.tsx
+++ b/Frontend/erp-system/app/dashboard/sales/invoices/new/page.tsx
@@ -11,8 +11,10 @@ import { Label } from "@/components/ui/label"
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select"
 import { Badge } from "@/components/ui/badge"
 import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table"
+import { formatUomName } from "@/lib/format-uom"
 import { cn } from "@/lib/utils"
 import { getSuggestedUnitPrice } from "@/lib/sales-line-utils"
+import { validateSalesDocument } from "@/lib/sales-validation"
 import { errorMessage } from "@/lib/error-map"
 import { salesApi } from "@/lib/api/sales"
 import { customersApi } from "@/lib/api/customers"
@@ -85,18 +87,9 @@ export default function NewSalesInvoicePage() {
         setItems(itemRes.items)
         setUoms(uomRes.items)
         setWarehouses(whRes.items)
-        const defaultWarehouseId = whRes.items[0]?.warehouseId ?? null
-        setCustomerId(cust.items[0]?.customerId ?? null)
-        setWarehouseId(defaultWarehouseId)
-        setLines([
-          {
-            ...blankLine("line-1"),
-            itemId: itemRes.items[0]?.itemId ?? 0,
-            uomId: itemRes.items[0]?.baseUomId ?? uomRes.items[0]?.uomId ?? 0,
-            warehouseId: defaultWarehouseId ?? 0,
-            unitPrice: getSuggestedUnitPrice(itemRes.items, itemRes.items[0]?.itemId),
-          },
-        ])
+        setCustomerId(null)
+        setWarehouseId(null)
+        setLines([blankLine("line-1")])
         setActiveFocSchemes(
           freeIssueRes.items.flatMap((issue) => {
             if (!issue.itemId) return []
@@ -132,6 +125,7 @@ export default function NewSalesInvoicePage() {
     updateLine(key, {
       itemId,
       uomId: item?.baseUomId ?? 0,
+      warehouseId: warehouseId ?? 0,
       unitPrice: getSuggestedUnitPrice(items, itemId),
     })
   }
@@ -178,10 +172,13 @@ export default function NewSalesInvoicePage() {
   const payableTotal = netTotal + taxTotal
 
   async function submit() {
-    if (!customerId || !warehouseId) return setSubmitError("Select a customer and warehouse.")
-    if (lines.some((line) => !line.itemId)) return setSubmitError("Select an item for every line.")
-    if (lines.some((line) => !line.warehouseId)) return setSubmitError("Select a warehouse for every line.")
-    if (lines.some((line) => !line.uomId)) return setSubmitError("Select a valid UOM for every line.")
+    const validationError = validateSalesDocument({
+      customerId,
+      warehouseId,
+      lines,
+      lineLabel: "invoice line",
+    })
+    if (validationError) return setSubmitError(validationError)
 
     const payload: CreateSalesInvoiceRequest = {
       customerId,
@@ -365,7 +362,7 @@ export default function NewSalesInvoicePage() {
                         <SelectContent>
                           {uoms.map((u) => (
                             <SelectItem key={u.uomId} value={String(u.uomId)}>
-                              {u.name}
+                              {formatUomName(u.name)}
                             </SelectItem>
                           ))}
                         </SelectContent>
diff --git a/Frontend/erp-system/app/dashboard/sales/invoices/page.tsx b/Frontend/erp-system/app/dashboard/sales/invoices/page.tsx
index d439ef7..9f09f1f 100644
--- a/Frontend/erp-system/app/dashboard/sales/invoices/page.tsx
+++ b/Frontend/erp-system/app/dashboard/sales/invoices/page.tsx
@@ -2,13 +2,15 @@
 
 import { useEffect, useMemo, useState } from "react"
 import Link from "next/link"
-import { ChevronLeft, ChevronRight, Eye, Filter, FileText, Plus, Printer } from "lucide-react"
+import { ChevronLeft, ChevronRight, Eye, FileText, Plus, Printer, Search } from "lucide-react"
 
 import { salesApi } from "@/lib/api/sales"
 import { errorMessage } from "@/lib/error-map"
 import { Button, buttonVariants } from "@/components/ui/button"
 import { Badge } from "@/components/ui/badge"
+import { Card, CardContent, CardHeader } from "@/components/ui/card"
 import { Input } from "@/components/ui/input"
+import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select"
 import { Skeleton } from "@/components/ui/skeleton"
 import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table"
 import { PaginationMeta } from "@/types/common"
@@ -18,7 +20,6 @@ import { cn } from "@/lib/utils"
 type StatusFilter = SalesInvoiceStatus | "All"
 
 const PAGE_SIZE = 10
-const tabs = ["All", "Draft", "Posted", "Cancelled"] as const
 
 function statusClass(status: SalesInvoiceStatus) {
   switch (status) {
@@ -95,36 +96,32 @@ export default function SalesInvoicesPage() {
         </div>
       </div>
 
-      <div className="rounded-2xl border bg-card shadow-sm">
-        <div className="flex flex-col gap-3 border-b px-4 py-4 lg:flex-row lg:items-center">
-          <div className="flex flex-wrap gap-2">
-            {tabs.map((t) => (
-              <button
-                key={t}
-                onClick={() => setStatus(t)}
-                className={cn(
-                  "rounded-full border px-3 py-1.5 text-xs font-medium transition-colors",
-                  status === t ? "border-primary bg-primary text-primary-foreground" : "border-border text-muted-foreground hover:text-foreground"
-                )}
-              >
-                {t}
-              </button>
-            ))}
+      <Card>
+        <CardHeader className="border-b">
+          <div className="flex flex-col gap-3 sm:flex-row sm:items-center">
+            <div className="relative flex-1 basis-0">
+              <Search className="pointer-events-none absolute top-1/2 left-4 size-5 -translate-y-1/2 text-muted-foreground" />
+              <Input
+                value={searchInput}
+                onChange={(e) => setSearchInput(e.target.value)}
+                placeholder="Search customer or invoice number"
+                className="h-14 w-full pl-11 text-base"
+                aria-label="Search invoices"
+              />
+            </div>
+            <Select<StatusFilter> value={status} onValueChange={(v) => setStatus(v ?? "All")}>
+              <SelectTrigger className="h-14! w-full flex-1 basis-0 text-base">
+                <SelectValue placeholder="All statuses" />
+              </SelectTrigger>
+              <SelectContent>
+                <SelectItem value="All" className="text-base">All statuses</SelectItem>
+                <SelectItem value="Draft" className="text-base">Draft</SelectItem>
+                <SelectItem value="Posted" className="text-base">Posted</SelectItem>
+                <SelectItem value="Cancelled" className="text-base">Cancelled</SelectItem>
+              </SelectContent>
+            </Select>
           </div>
-
-          <div className="flex flex-1 flex-col gap-3 lg:flex-row lg:items-center lg:justify-end">
-            <Input
-              value={searchInput}
-              onChange={(e) => setSearchInput(e.target.value)}
-              placeholder="Filter by customer or invoice number"
-              className="h-12 w-full lg:max-w-sm"
-            />
-            <Button variant="outline" size="sm" className="lg:ml-auto">
-              <Filter className="size-4" />
-              Advanced
-            </Button>
-          </div>
-        </div>
+        </CardHeader>
 
         {error && <div className="mx-4 mt-4 rounded-lg border border-destructive/30 bg-destructive/5 p-5 text-base text-destructive">{error}</div>}
 
@@ -145,6 +142,7 @@ export default function SalesInvoicesPage() {
 
         {!error && rows !== null && visibleRows.length > 0 && (
           <>
+            <CardContent className="px-0">
             <div className="overflow-x-auto">
               <Table className="text-base">
                 <TableHeader>
@@ -195,6 +193,7 @@ export default function SalesInvoicesPage() {
                 </TableBody>
               </Table>
             </div>
+            </CardContent>
 
             <div className="border-t px-4 py-3">
               <div className="grid gap-3 text-sm md:grid-cols-3">
@@ -233,7 +232,7 @@ export default function SalesInvoicesPage() {
             )}
           </>
         )}
-      </div>
+      </Card>
     </div>
   )
 }
diff --git a/Frontend/erp-system/app/dashboard/sales/page.tsx b/Frontend/erp-system/app/dashboard/sales/page.tsx
index ad9c562..98982c9 100644
--- a/Frontend/erp-system/app/dashboard/sales/page.tsx
+++ b/Frontend/erp-system/app/dashboard/sales/page.tsx
@@ -1,7 +1,8 @@
 import Link from "next/link"
-import { FileBarChart, FileText, PackageX, ReceiptText, ShoppingCart } from "lucide-react"
+import { FileText, PackageX, ReceiptText, ShoppingCart } from "lucide-react"
 
 import { buttonVariants } from "@/components/ui/button"
+import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card"
 import { cn } from "@/lib/utils"
 
 const sections = [
@@ -34,36 +35,38 @@ const sections = [
 export default function SalesHubPage() {
   return (
     <div className="flex flex-col gap-6">
-      <div className="flex items-start justify-between gap-4">
+      <div className="flex flex-col gap-3 sm:flex-row sm:items-center sm:justify-between">
         <div>
           <div className="mb-3 inline-flex items-center gap-2 rounded-full bg-primary/10 px-3 py-1 text-sm font-medium text-primary">
             <ReceiptText className="size-4" />
             Sales
           </div>
           <h1 className="text-2xl font-bold text-foreground">Sales</h1>
-          <p className="text-base text-muted-foreground">
-            Invoices, slips, and free issues in one place.
-          </p>
+          <p className="text-base text-muted-foreground">Invoices, slips, and free issues in one place.</p>
         </div>
       </div>
 
-      <div className="grid gap-4 md:grid-cols-2 xl:grid-cols-4">
+      <div className="grid gap-4 md:grid-cols-2 xl:grid-cols-3">
         {sections.map((section) => {
           const Icon = section.icon
           return (
             <Link
               key={section.href}
               href={section.href}
-              className="group rounded-2xl border bg-card p-5 shadow-sm transition-all hover:-translate-y-0.5 hover:shadow-md"
+              className="block focus-visible:outline-none"
             >
-              <div className="mb-4 flex size-11 items-center justify-center rounded-2xl bg-primary/10 text-primary">
-                <Icon className="size-5" />
-              </div>
-              <h2 className="text-lg font-semibold text-foreground">{section.title}</h2>
-              <p className="mt-1 text-sm leading-6 text-muted-foreground">{section.description}</p>
-              <div className={cn(buttonVariants({ variant: "ghost", size: "sm" }), "mt-4 px-0 text-primary")}>
-                Open
-              </div>
+              <Card className="h-full transition-all duration-200 hover:-translate-y-0.5 hover:ring-primary/30 hover:shadow-lg">
+                <CardHeader>
+                  <div className="mb-2 flex size-11 items-center justify-center rounded-xl bg-primary/10 text-primary">
+                    <Icon className="size-5" />
+                  </div>
+                  <CardTitle className="text-lg font-semibold">{section.title}</CardTitle>
+                  <CardDescription className="text-base">{section.description}</CardDescription>
+                </CardHeader>
+                <CardContent>
+                  <div className={cn(buttonVariants({ variant: "ghost", size: "sm" }), "px-0 text-primary")}>Open</div>
+                </CardContent>
+              </Card>
             </Link>
           )
         })}
diff --git a/Frontend/erp-system/app/dashboard/sales/slips/page.tsx b/Frontend/erp-system/app/dashboard/sales/slips/page.tsx
index ad31b4a..0787b3e 100644
--- a/Frontend/erp-system/app/dashboard/sales/slips/page.tsx
+++ b/Frontend/erp-system/app/dashboard/sales/slips/page.tsx
@@ -2,13 +2,15 @@
 
 import { useEffect, useMemo, useState } from "react"
 import Link from "next/link"
-import { ChevronLeft, ChevronRight, Eye, Filter, Package2, Plus, Printer } from "lucide-react"
+import { ChevronLeft, ChevronRight, Eye, Package2, Plus, Printer, Search } from "lucide-react"
 
 import { salesApi } from "@/lib/api/sales"
 import { errorMessage } from "@/lib/error-map"
 import { Button, buttonVariants } from "@/components/ui/button"
 import { Badge } from "@/components/ui/badge"
+import { Card, CardContent, CardHeader } from "@/components/ui/card"
 import { Input } from "@/components/ui/input"
+import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select"
 import { Skeleton } from "@/components/ui/skeleton"
 import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table"
 import { cn } from "@/lib/utils"
@@ -18,7 +20,6 @@ import { SalesSlipStatus, SalesSlipSummary } from "@/types/sales"
 type StatusFilter = SalesSlipStatus | "All"
 
 const PAGE_SIZE = 10
-const tabs = ["All", "Draft", "Posted", "Cancelled"] as const
 
 function statusClass(status: SalesSlipStatus) {
   switch (status) {
@@ -95,36 +96,32 @@ export default function SalesSlipsPage() {
         </div>
       </div>
 
-      <div className="rounded-2xl border bg-card shadow-sm">
-        <div className="flex flex-col gap-3 border-b px-4 py-4 lg:flex-row lg:items-center">
-          <div className="flex flex-wrap gap-2">
-            {tabs.map((t) => (
-              <button
-                key={t}
-                onClick={() => setStatus(t)}
-                className={cn(
-                  "rounded-full border px-3 py-1.5 text-xs font-medium transition-colors",
-                  status === t ? "border-primary bg-primary text-primary-foreground" : "border-border text-muted-foreground hover:text-foreground"
-                )}
-              >
-                {t}
-              </button>
-            ))}
+      <Card>
+        <CardHeader className="border-b">
+          <div className="flex flex-col gap-3 sm:flex-row sm:items-center">
+            <div className="relative flex-1 basis-0">
+              <Search className="pointer-events-none absolute top-1/2 left-4 size-5 -translate-y-1/2 text-muted-foreground" />
+              <Input
+                value={searchInput}
+                onChange={(e) => setSearchInput(e.target.value)}
+                placeholder="Search customer or slip number"
+                className="h-14 w-full pl-11 text-base"
+                aria-label="Search slips"
+              />
+            </div>
+            <Select<StatusFilter> value={status} onValueChange={(v) => setStatus(v ?? "All")}>
+              <SelectTrigger className="h-14! w-full flex-1 basis-0 text-base">
+                <SelectValue placeholder="All statuses" />
+              </SelectTrigger>
+              <SelectContent>
+                <SelectItem value="All" className="text-base">All statuses</SelectItem>
+                <SelectItem value="Draft" className="text-base">Draft</SelectItem>
+                <SelectItem value="Posted" className="text-base">Posted</SelectItem>
+                <SelectItem value="Cancelled" className="text-base">Cancelled</SelectItem>
+              </SelectContent>
+            </Select>
           </div>
-
-          <div className="flex flex-1 flex-col gap-3 lg:flex-row lg:items-center lg:justify-end">
-            <Input
-              value={searchInput}
-              onChange={(e) => setSearchInput(e.target.value)}
-              placeholder="Filter by customer or slip number"
-              className="h-12 w-full lg:max-w-sm"
-            />
-            <Button variant="outline" size="sm" className="lg:ml-auto">
-              <Filter className="size-4" />
-              Advanced
-            </Button>
-          </div>
-        </div>
+        </CardHeader>
 
         {error && <div className="mx-4 mt-4 rounded-lg border border-destructive/30 bg-destructive/5 p-5 text-base text-destructive">{error}</div>}
 
@@ -145,6 +142,7 @@ export default function SalesSlipsPage() {
 
         {!error && rows !== null && visibleRows.length > 0 && (
           <>
+            <CardContent className="px-0">
             <div className="overflow-x-auto">
               <Table className="text-base">
                 <TableHeader>
@@ -191,6 +189,7 @@ export default function SalesSlipsPage() {
                 </TableBody>
               </Table>
             </div>
+            </CardContent>
 
             <div className="border-t px-4 py-3">
               <div className="grid gap-3 text-sm md:grid-cols-3">
@@ -229,7 +228,7 @@ export default function SalesSlipsPage() {
             )}
           </>
         )}
-      </div>
+      </Card>
     </div>
   )
 }