feat: searchable accounting code picker + cost centres grouped by site

Accounting Code search (new/edit/import/manager-edit PO forms):
- New SearchableSelect component (components/ui/searchable-select.tsx):
  type-to-filter by code or name, results grouped by sub-category with
  sticky headers, highlighted selected item, clear button, Escape/outside-click
  to dismiss
- Replaces the plain <select> for the main Accounting Code field on all PO forms
- LineItemsEditor per-row account column also uses SearchableSelect (compact size)
  when multi-account mode is active

Cost Centre dropdown reorganised by site:
- New type CostCentreGroup replaces flat CostCentreOption
- Each site becomes an <optgroup> label (unselectable); the site itself is the
  first selectable option inside ("Haldia (Site)"), followed by its vessels
- Vessels with no site assigned appear under an "Unassigned Vessels" group
- Shared helpers buildCostCentreGroups() and buildAccountGroups() in
  lib/cost-centre-groups.ts — used by all four PO form pages

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

App/app/(portal)/approvals/[id]/manager-edit-po-form.tsx

@@ -7,7 +7,8 @@ import { LineItemsEditor } from "@/components/po/po-line-items-editor";
 import { TC_DEFAULTS, TC_FIXED_LINE } from "@/lib/validations/po";
 import type { LineItemInput } from "@/lib/validations/po";
 import type { Vendor, PurchaseOrder } from "@prisma/client";
-import type { CostCentreOption, AccountGroup } from "@/app/(portal)/po/new/new-po-form";
+import type { CostCentreGroup, AccountGroup } from "@/app/(portal)/po/new/new-po-form";
+import { SearchableSelect } from "@/components/ui/searchable-select";
 
 type SerializedLineItem = {
   id: string;
@@ -34,7 +35,7 @@ type PoFull = Omit<PurchaseOrder, "totalAmount"> & {
 
 interface Props {
   po: PoFull;
-  costCentres: CostCentreOption[];
+  costCentres: CostCentreGroup[];
   initialCostCentreRef: string;
   accounts: AccountGroup[];
   vendors: Vendor[];
@@ -44,6 +45,12 @@ const INPUT =
   "w-full rounded-lg border border-amber-300 bg-amber-50 px-3 py-2 text-sm focus:border-amber-500 focus:outline-none focus:ring-2 focus:ring-amber-400/30 placeholder:text-neutral-400";
 const LABEL = "block text-xs font-semibold text-amber-800 mb-1";
 
+/** Controlled account picker so SearchableSelect can be used inside the uncontrolled manager form */
+function ManagerAccountSelect({ accountId, accounts }: { accountId: string; accounts: AccountGroup[] }) {
+  const [value, setValue] = useState(accountId);
+  return <SearchableSelect name="accountId" value={value} onChange={setValue} groups={accounts} placeholder="Search accounting code…" required />;
+}
+
 export function ManagerEditPoForm({ po, costCentres, initialCostCentreRef, accounts, vendors }: Props) {
   const router = useRouter();
   const [editing, setEditing] = useState(false);
@@ -154,27 +161,25 @@ export function ManagerEditPoForm({ po, costCentres, initialCostCentreRef, accou
             <div>
               <label className={LABEL}>Cost Centre <span className="text-danger">*</span></label>
               <select name="costCentreRef" required defaultValue={initialCostCentreRef} className={INPUT}>
-                <optgroup label="Vessels">
-                  {costCentres.filter((c) => c.group === "Vessels").map((c) => (
-                    <option key={c.ref} value={c.ref}>{c.label}</option>
-                  ))}
-                </optgroup>
-                <optgroup label="Sites">
-                  {costCentres.filter((c) => c.group === "Sites").map((c) => (
-                    <option key={c.ref} value={c.ref}>{c.label}</option>
-                  ))}
-                </optgroup>
+                <option value="">Select cost centre…</option>
+                {costCentres.map((group) => (
+                  <optgroup key={group.siteId ?? "__unassigned"} label={group.siteName}>
+                    {group.siteRef && (
+                      <option value={group.siteRef}>{group.siteName} (Site)</option>
+                    )}
+                    {group.vessels.map((v) => (
+                      <option key={v.ref} value={v.ref}>{v.label}</option>
+                    ))}
+                  </optgroup>
+                ))}
               </select>
             </div>
             <div>
               <label className={LABEL}>Accounting Code <span className="text-danger">*</span></label>
-              <select name="accountId" required defaultValue={po.accountId} className={INPUT}>
-                {accounts.map(({ group, items }) => (
-                  <optgroup key={group} label={group}>
-                    {items.map((a) => <option key={a.id} value={a.id}>{a.code} — {a.name}</option>)}
-                  </optgroup>
-                ))}
-              </select>
+              <ManagerAccountSelect
+                accountId={po.accountId}
+                accounts={accounts}
+              />
             </div>
             <div>
               <label className={LABEL}>Project Code</label>

App/app/(portal)/approvals/[id]/page.tsx

@@ -5,7 +5,7 @@ import { notFound, redirect } from "next/navigation";
 import { ApprovalActions } from "./approval-actions";
 import { PoDetail } from "@/components/po/po-detail";
 import { ManagerEditPoForm } from "./manager-edit-po-form";
-import type { CostCentreOption, AccountGroup } from "@/app/(portal)/po/new/new-po-form";
+import { buildCostCentreGroups, buildAccountGroups } from "@/lib/cost-centre-groups";
 import type { Metadata } from "next";
 
 interface Props {
@@ -44,8 +44,8 @@ export default async function ApprovalDetailPage({ params }: Props) {
         receipt: true,
       },
     }),
-    db.vessel.findMany({ where: { isActive: true }, orderBy: { name: "asc" }, select: { id: true, name: true, code: true } }),
-    db.site.findMany({ where: { isActive: true }, orderBy: { name: "asc" }, select: { id: true, name: true, code: true } }),
+    db.vessel.findMany({ where: { isActive: true }, orderBy: { name: "asc" }, select: { id: true, name: true, code: true, siteId: true } }),
+    db.site.findMany({ where: { isActive: true }, orderBy: { name: "asc" }, select: { id: true, name: true } }),
     db.account.findMany({
       where: { isActive: true, children: { none: {} } },
       orderBy: { code: "asc" },
@@ -57,20 +57,8 @@ export default async function ApprovalDetailPage({ params }: Props) {
   if (!po) notFound();
   if (po.status !== "MGR_REVIEW") redirect(`/po/${id}`);
 
-  const accountGroupMap = new Map<string, typeof accounts>();
-  for (const a of accounts) {
-    const subLabel = a.parent ? `${a.parent.code} — ${a.parent.name}` : "Uncategorised";
-    const topLabel = a.parent?.parent ? `${a.parent.parent.name} › ` : "";
-    const groupKey = `${topLabel}${subLabel}`;
-    if (!accountGroupMap.has(groupKey)) accountGroupMap.set(groupKey, []);
-    accountGroupMap.get(groupKey)!.push(a);
-  }
-  const accountGroups: AccountGroup[] = Array.from(accountGroupMap.entries()).map(([group, items]) => ({ group, items }));
-
-  const costCentres: CostCentreOption[] = [
-    ...vessels.map((v) => ({ ref: `v:${v.id}`, label: `${v.code} — ${v.name}`, group: "Vessels" as const })),
-    ...sites.map((s) => ({ ref: `s:${s.id}`, label: `${s.code} — ${s.name}`, group: "Sites" as const })),
-  ];
+  const costCentres = buildCostCentreGroups(vessels, sites);
+  const accountGroups = buildAccountGroups(accounts);
   const initialCostCentreRef = po ? (po.vesselId ? `v:${po.vesselId}` : po.siteId ? `s:${po.siteId}` : "") : "";
 
   const serializedPo = {

App/app/(portal)/po/[id]/edit/edit-po-form.tsx

@@ -4,8 +4,9 @@ import { useState } from "react";
 import { useRouter } from "next/navigation";
 import { updatePo } from "./actions";
 import type { Vendor, PurchaseOrder } from "@prisma/client";
-import type { CostCentreOption, AccountGroup } from "@/app/(portal)/po/new/new-po-form";
+import type { CostCentreGroup, AccountGroup } from "@/app/(portal)/po/new/new-po-form";
 import { LineItemsEditor } from "@/components/po/po-line-items-editor";
+import { SearchableSelect } from "@/components/ui/searchable-select";
 import type { LineItemInput } from "@/lib/validations/po";
 import { TC_DEFAULTS, TC_FIXED_LINE, TC_FIXED_LINE_2 } from "@/lib/validations/po";
 
@@ -35,7 +36,7 @@ type PoWithItems = Omit<PurchaseOrder, "totalAmount"> & {
 
 interface Props {
   po: PoWithItems;
-  costCentres: CostCentreOption[];
+  costCentres: CostCentreGroup[];
   initialCostCentreRef: string;
   accounts: AccountGroup[];
   vendors: Vendor[];
@@ -132,16 +133,16 @@ export function EditPoForm({ po, costCentres, initialCostCentreRef, accounts, ve
             </label>
             <select name="costCentreRef" required defaultValue={initialCostCentreRef} className={INPUT_CLS}>
               <option value="">Select cost centre…</option>
-              <optgroup label="Vessels">
-                {costCentres.filter((c) => c.group === "Vessels").map((c) => (
-                  <option key={c.ref} value={c.ref}>{c.label}</option>
-                ))}
-              </optgroup>
-              <optgroup label="Sites">
-                {costCentres.filter((c) => c.group === "Sites").map((c) => (
-                  <option key={c.ref} value={c.ref}>{c.label}</option>
-                ))}
-              </optgroup>
+              {costCentres.map((group) => (
+                <optgroup key={group.siteId ?? "__unassigned"} label={group.siteName}>
+                  {group.siteRef && (
+                    <option value={group.siteRef}>{group.siteName} (Site)</option>
+                  )}
+                  {group.vessels.map((v) => (
+                    <option key={v.ref} value={v.ref}>{v.label}</option>
+                  ))}
+                </optgroup>
+              ))}
             </select>
           </div>
           <div>
@@ -159,20 +160,14 @@ export function EditPoForm({ po, costCentres, initialCostCentreRef, accounts, ve
                 Multiple accounts
               </label>
             </div>
-            <select
+            <SearchableSelect
               name="accountId"
-              required
               value={defaultAccountId}
-              onChange={(e) => setDefaultAccountId(e.target.value)}
-              className={INPUT_CLS}
-            >
-              <option value="">Select accounting code…</option>
-              {accounts.map(({ group, items }) => (
-                <optgroup key={group} label={group}>
-                  {items.map((a) => <option key={a.id} value={a.id}>{a.code} — {a.name}</option>)}
-                </optgroup>
-              ))}
-            </select>
+              onChange={setDefaultAccountId}
+              groups={accounts}
+              placeholder="Search accounting code…"
+              required
+            />
           </div>
           <div>
             <label className="block text-sm font-medium text-neutral-700 mb-1.5">Project Code</label>
@@ -231,7 +226,7 @@ export function EditPoForm({ po, costCentres, initialCostCentreRef, accounts, ve
           items={lineItems}
           onChange={setLineItems}
           multiAccount={multiAccount}
-          accounts={accounts.flatMap((g) => g.items.map((a) => ({ id: a.id, name: a.name, code: a.code })))}
+          accounts={accounts}
           defaultAccountId={defaultAccountId || undefined}
         />
       </section>

App/app/(portal)/po/[id]/edit/page.tsx

@@ -2,7 +2,7 @@ import { auth } from "@/auth";
 import { db } from "@/lib/db";
 import { notFound, redirect } from "next/navigation";
 import { EditPoForm } from "./edit-po-form";
-import type { CostCentreOption, AccountGroup } from "@/app/(portal)/po/new/new-po-form";
+import { buildCostCentreGroups, buildAccountGroups } from "@/lib/cost-centre-groups";
 import type { Metadata } from "next";
 
 interface Props {
@@ -26,13 +26,12 @@ export default async function EditPoPage({ params }: Props) {
 
   if (!["DRAFT", "EDITS_REQUESTED"].includes(po.status)) redirect(`/po/${id}`);
 
-  const canEdit =
-    po.submitterId === session.user.id || session.user.role === "SUPERUSER";
+  const canEdit = po.submitterId === session.user.id || session.user.role === "SUPERUSER";
   if (!canEdit) redirect(`/po/${id}`);
 
-  const [vessels, sites, accounts, vendors, noteAction] = await Promise.all([
-    db.vessel.findMany({ where: { isActive: true }, orderBy: { name: "asc" }, select: { id: true, name: true, code: true } }),
-    db.site.findMany({ where: { isActive: true }, orderBy: { name: "asc" }, select: { id: true, name: true, code: true } }),
+  const [vessels, sites, leafAccounts, vendors, noteAction] = await Promise.all([
+    db.vessel.findMany({ where: { isActive: true }, orderBy: { name: "asc" }, select: { id: true, name: true, code: true, siteId: true } }),
+    db.site.findMany({ where: { isActive: true }, orderBy: { name: "asc" }, select: { id: true, name: true } }),
     db.account.findMany({
       where: { isActive: true, children: { none: {} } },
       orderBy: { code: "asc" },
@@ -48,20 +47,8 @@ export default async function EditPoPage({ params }: Props) {
       : Promise.resolve(null),
   ]);
 
-  const accountGroupMap = new Map<string, typeof accounts>();
-  for (const a of accounts) {
-    const subLabel = a.parent ? `${a.parent.code} — ${a.parent.name}` : "Uncategorised";
-    const topLabel = a.parent?.parent ? `${a.parent.parent.name} › ` : "";
-    const groupKey = `${topLabel}${subLabel}`;
-    if (!accountGroupMap.has(groupKey)) accountGroupMap.set(groupKey, []);
-    accountGroupMap.get(groupKey)!.push(a);
-  }
-  const accountGroups: AccountGroup[] = Array.from(accountGroupMap.entries()).map(([group, items]) => ({ group, items }));
-
-  const costCentres: CostCentreOption[] = [
-    ...vessels.map((v) => ({ ref: `v:${v.id}`, label: `${v.code} — ${v.name}`, group: "Vessels" as const })),
-    ...sites.map((s) => ({ ref: `s:${s.id}`, label: `${s.code} — ${s.name}`, group: "Sites" as const })),
-  ];
+  const costCentres = buildCostCentreGroups(vessels, sites);
+  const accountGroups = buildAccountGroups(leafAccounts);
   const initialCostCentreRef = po.vesselId ? `v:${po.vesselId}` : po.siteId ? `s:${po.siteId}` : "";
 
   const serializedPo = {
@@ -82,7 +69,14 @@ export default async function EditPoPage({ params }: Props) {
         <h1 className="text-2xl font-semibold text-neutral-900">Edit Purchase Order</h1>
         <p className="mt-1 text-sm text-neutral-500 font-mono">{po.poNumber}</p>
       </div>
-      <EditPoForm po={serializedPo} costCentres={costCentres} initialCostCentreRef={initialCostCentreRef} accounts={accountGroups} vendors={vendors} managerNoteAuthor={noteAction?.actor.name ?? null} />
+      <EditPoForm
+        po={serializedPo}
+        costCentres={costCentres}
+        initialCostCentreRef={initialCostCentreRef}
+        accounts={accountGroups}
+        vendors={vendors}
+        managerNoteAuthor={noteAction?.actor.name ?? null}
+      />
     </div>
   );
 }

App/app/(portal)/po/import/import-form.tsx

@@ -3,7 +3,8 @@
 import { useState, useRef } from "react";
 import { useRouter } from "next/navigation";
 import type { Vendor } from "@prisma/client";
-import type { CostCentreOption, AccountGroup } from "@/app/(portal)/po/new/new-po-form";
+import type { CostCentreGroup, AccountGroup } from "@/app/(portal)/po/new/new-po-form";
+import { SearchableSelect } from "@/components/ui/searchable-select";
 import { importPo } from "./actions";
 import type { ParsedImport } from "@/app/api/po/import/route";
 import { formatCurrency } from "@/lib/utils";
@@ -12,7 +13,7 @@ const INPUT_CLS =
   "w-full rounded-lg border border-neutral-300 px-3 py-2.5 text-sm focus:border-primary-500 focus:outline-none focus:ring-2 focus:ring-primary-500/20";
 
 interface Props {
-  costCentres: CostCentreOption[];
+  costCentres: CostCentreGroup[];
   accounts: AccountGroup[];
   vendors: Vendor[];
 }
@@ -65,7 +66,7 @@ export function ImportForm({ costCentres, accounts, vendors }: Props) {
         title: parsed.vendorName
           ? `${parsed.vendorName} — Import`
           : "Imported Purchase Order",
-        costCentreRef: costCentres[0]?.ref ?? "",
+        costCentreRef: costCentres[0]?.siteRef ?? costCentres[0]?.vessels[0]?.ref ?? "",
         accountId: accounts[0]?.items[0]?.id ?? "",
         vendorId: matchedVendor?.id ?? "",
       });
@@ -189,35 +190,30 @@ export function ImportForm({ costCentres, accounts, vendors }: Props) {
               className={INPUT_CLS}
             >
               <option value="">Select cost centre…</option>
-              <optgroup label="Vessels">
-                {costCentres.filter((c) => c.group === "Vessels").map((c) => (
-                  <option key={c.ref} value={c.ref}>{c.label}</option>
-                ))}
-              </optgroup>
-              <optgroup label="Sites">
-                {costCentres.filter((c) => c.group === "Sites").map((c) => (
-                  <option key={c.ref} value={c.ref}>{c.label}</option>
-                ))}
-              </optgroup>
+              {costCentres.map((group) => (
+                <optgroup key={group.siteId ?? "__unassigned"} label={group.siteName}>
+                  {group.siteRef && (
+                    <option value={group.siteRef}>{group.siteName} (Site)</option>
+                  )}
+                  {group.vessels.map((v) => (
+                    <option key={v.ref} value={v.ref}>{v.label}</option>
+                  ))}
+                </optgroup>
+              ))}
             </select>
           </div>
           <div>
             <label className="block text-sm font-medium text-neutral-700 mb-1.5">
               Accounting Code <span className="text-danger">*</span>
             </label>
-            <select
+            <SearchableSelect
+              name="__import_account"
               value={preview.accountId}
-              onChange={(e) => setPreview({ ...preview, accountId: e.target.value })}
+              onChange={(v) => setPreview({ ...preview, accountId: v })}
+              groups={accounts}
+              placeholder="Search accounting code…"
               required
-              className={INPUT_CLS}
-            >
-              <option value="">Select accounting code…</option>
-              {accounts.map(({ group, items }) => (
-                <optgroup key={group} label={group}>
-                  {items.map((a) => <option key={a.id} value={a.id}>{a.code} — {a.name}</option>)}
-                </optgroup>
-              ))}
-            </select>
+            />
           </div>
         </div>
         <div>

App/app/(portal)/po/import/page.tsx

@@ -2,7 +2,7 @@ import { auth } from "@/auth";
 import { db } from "@/lib/db";
 import { redirect } from "next/navigation";
 import { ImportForm } from "./import-form";
-import type { CostCentreOption, AccountGroup } from "@/app/(portal)/po/new/new-po-form";
+import { buildCostCentreGroups, buildAccountGroups } from "@/lib/cost-centre-groups";
 import type { Metadata } from "next";
 
 export const metadata: Metadata = { title: "Import Purchase Order" };
@@ -14,9 +14,9 @@ export default async function ImportPoPage() {
   const { role } = session.user;
   if (!["MANAGER", "SUPERUSER", "ADMIN"].includes(role)) redirect("/dashboard");
 
-  const [vessels, sites, accounts, vendors] = await Promise.all([
-    db.vessel.findMany({ where: { isActive: true }, orderBy: { name: "asc" }, select: { id: true, name: true, code: true } }),
-    db.site.findMany({ where: { isActive: true }, orderBy: { name: "asc" }, select: { id: true, name: true, code: true } }),
+  const [vessels, sites, leafAccounts, vendors] = await Promise.all([
+    db.vessel.findMany({ where: { isActive: true }, orderBy: { name: "asc" }, select: { id: true, name: true, code: true, siteId: true } }),
+    db.site.findMany({ where: { isActive: true }, orderBy: { name: "asc" }, select: { id: true, name: true } }),
     db.account.findMany({
       where: { isActive: true, children: { none: {} } },
       orderBy: { code: "asc" },
@@ -25,20 +25,8 @@ export default async function ImportPoPage() {
     db.vendor.findMany({ orderBy: { name: "asc" } }),
   ]);
 
-  const accountGroupMap = new Map<string, typeof accounts>();
-  for (const a of accounts) {
-    const subLabel = a.parent ? `${a.parent.code} — ${a.parent.name}` : "Uncategorised";
-    const topLabel = a.parent?.parent ? `${a.parent.parent.name} › ` : "";
-    const groupKey = `${topLabel}${subLabel}`;
-    if (!accountGroupMap.has(groupKey)) accountGroupMap.set(groupKey, []);
-    accountGroupMap.get(groupKey)!.push(a);
-  }
-  const accountGroups: AccountGroup[] = Array.from(accountGroupMap.entries()).map(([group, items]) => ({ group, items }));
-
-  const costCentres: CostCentreOption[] = [
-    ...vessels.map((v) => ({ ref: `v:${v.id}`, label: `${v.code} — ${v.name}`, group: "Vessels" as const })),
-    ...sites.map((s) => ({ ref: `s:${s.id}`, label: `${s.code} — ${s.name}`, group: "Sites" as const })),
-  ];
+  const costCentres = buildCostCentreGroups(vessels, sites);
+  const accounts = buildAccountGroups(leafAccounts);
 
   return (
     <div className="max-w-6xl">
@@ -49,7 +37,7 @@ export default async function ImportPoPage() {
           You then select the cost centre, accounting code, and confirm before saving as a draft.
         </p>
       </div>
-      <ImportForm costCentres={costCentres} accounts={accountGroups} vendors={vendors} />
+      <ImportForm costCentres={costCentres} accounts={accounts} vendors={vendors} />
     </div>
   );
 }

App/app/(portal)/po/new/new-po-form.tsx

@@ -6,11 +6,20 @@ import { createPo } from "./actions";
 import type { Vendor } from "@prisma/client";
 import { LineItemsEditor } from "@/components/po/po-line-items-editor";
 import { FileUploader } from "@/components/po/file-uploader";
+import { SearchableSelect } from "@/components/ui/searchable-select";
 import { uploadAndLinkFiles } from "@/lib/upload-files";
 import type { LineItemInput } from "@/lib/validations/po";
 import { TC_DEFAULTS, TC_FIXED_LINE, TC_FIXED_LINE_2 } from "@/lib/validations/po";
 
-export type CostCentreOption = { ref: string; label: string; group: "Vessels" | "Sites" };
+// Cost centres grouped by site: the site itself is selectable, vessels are listed under it
+export type CostCentreGroup = {
+  siteId: string | null;  // null = "Unassigned Vessels" fallback group
+  siteName: string;
+  siteRef: string | null; // "s:siteId" — selectable; null = no site option
+  vessels: { ref: string; label: string }[];
+};
+
+// Accounting codes grouped by sub-category
 export type AccountGroup = { group: string; items: { id: string; code: string; name: string }[] };
 
 const INPUT_CLS =
@@ -19,7 +28,7 @@ const INPUT_CLS =
 const EMPTY_LINE: LineItemInput = { name: "", description: "", quantity: 1, unit: "pc", size: "", unitPrice: 0, gstRate: 0.18 };
 
 interface Props {
-  costCentres: CostCentreOption[];
+  costCentres: CostCentreGroup[];
   accounts: AccountGroup[];
   vendors: Vendor[];
   initialLineItems?: LineItemInput[];
@@ -86,24 +95,28 @@ export function NewPoForm({ costCentres, accounts, vendors, initialLineItems, in
             </label>
             <input name="title" required className={INPUT_CLS} placeholder="Brief description of what is being ordered" />
           </div>
+
+          {/* Cost Centre — grouped by site */}
           <div>
             <label className="block text-sm font-medium text-neutral-700 mb-1.5">
               Cost Centre <span className="text-danger">*</span>
             </label>
             <select name="costCentreRef" required defaultValue={initialCostCentreRef ?? ""} className={INPUT_CLS}>
               <option value="">Select cost centre…</option>
-              <optgroup label="Vessels">
-                {costCentres.filter((c) => c.group === "Vessels").map((c) => (
-                  <option key={c.ref} value={c.ref}>{c.label}</option>
-                ))}
-              </optgroup>
-              <optgroup label="Sites">
-                {costCentres.filter((c) => c.group === "Sites").map((c) => (
-                  <option key={c.ref} value={c.ref}>{c.label}</option>
-                ))}
-              </optgroup>
+              {costCentres.map((group) => (
+                <optgroup key={group.siteId ?? "__unassigned"} label={group.siteName}>
+                  {group.siteRef && (
+                    <option value={group.siteRef}>{group.siteName} (Site)</option>
+                  )}
+                  {group.vessels.map((v) => (
+                    <option key={v.ref} value={v.ref}>{v.label}</option>
+                  ))}
+                </optgroup>
+              ))}
             </select>
           </div>
+
+          {/* Accounting Code — searchable */}
           <div>
             <div className="flex items-center justify-between mb-1.5">
               <label className="text-sm font-medium text-neutral-700">
@@ -116,24 +129,19 @@ export function NewPoForm({ costCentres, accounts, vendors, initialLineItems, in
                   onChange={(e) => setMultiAccount(e.target.checked)}
                   className="rounded border-neutral-300"
                 />
-                Multiple accounts
+                Per-item codes
               </label>
             </div>
-            <select
+            <SearchableSelect
               name="accountId"
-              required
               value={defaultAccountId}
-              onChange={(e) => setDefaultAccountId(e.target.value)}
-              className={INPUT_CLS}
-            >
-              <option value="">Select accounting code…</option>
-              {accounts.map(({ group, items }) => (
-                <optgroup key={group} label={group}>
-                  {items.map((a) => <option key={a.id} value={a.id}>{a.code} — {a.name}</option>)}
-                </optgroup>
-              ))}
-            </select>
+              onChange={setDefaultAccountId}
+              groups={accounts}
+              placeholder="Search accounting code…"
+              required
+            />
           </div>
+
           <div>
             <label className="block text-sm font-medium text-neutral-700 mb-1.5">Project Code</label>
             <input name="projectCode" className={INPUT_CLS} placeholder="Optional" />
@@ -196,7 +204,7 @@ export function NewPoForm({ costCentres, accounts, vendors, initialLineItems, in
           items={lineItems}
           onChange={setLineItems}
           multiAccount={multiAccount}
-          accounts={accounts.flatMap((g) => g.items.map((a) => ({ id: a.id, name: a.name, code: a.code })))}
+          accounts={accounts}
           defaultAccountId={defaultAccountId || undefined}
         />
       </section>
@@ -241,22 +249,13 @@ export function NewPoForm({ costCentres, accounts, vendors, initialLineItems, in
             <div key={name} className="flex items-center gap-3">
               <span className="w-5 shrink-0 text-sm font-medium text-neutral-500 text-right">{n}.</span>
               <label className="w-44 shrink-0 text-sm font-medium text-neutral-700">{label}</label>
-              <input
-                name={name}
-                defaultValue={TC_DEFAULTS[key]}
-                className={INPUT_CLS}
-              />
+              <input name={name} defaultValue={TC_DEFAULTS[key]} className={INPUT_CLS} />
             </div>
           ))}
           <div className="flex items-start gap-3">
             <span className="w-5 shrink-0 text-sm font-medium text-neutral-500 text-right mt-2.5">7.</span>
             <label className="w-44 shrink-0 text-sm font-medium text-neutral-700 mt-2.5">Others</label>
-            <textarea
-              name="tcOthers"
-              rows={2}
-              defaultValue=""
-              className={INPUT_CLS}
-            />
+            <textarea name="tcOthers" rows={2} defaultValue="" className={INPUT_CLS} />
           </div>
           <div className="rounded-lg bg-neutral-50 border border-neutral-200 px-3 py-2.5 text-sm text-neutral-500 select-none">
             <span className="font-medium text-neutral-600">8.</span> {TC_FIXED_LINE_2}

App/app/(portal)/po/new/page.tsx

@@ -3,7 +3,7 @@ import { db } from "@/lib/db";
 import { hasPermission } from "@/lib/permissions";
 import { redirect } from "next/navigation";
 import { NewPoForm } from "./new-po-form";
-import type { CostCentreOption } from "./new-po-form";
+import { buildCostCentreGroups, buildAccountGroups } from "@/lib/cost-centre-groups";
 import type { Metadata } from "next";
 import type { LineItemInput } from "@/lib/validations/po";
 import type { CartItem } from "@/lib/cart";
@@ -40,7 +40,6 @@ export default async function NewPoPage({ searchParams }: Props) {
           gstRate: 0.18,
           productId: item.productId,
         }));
-        // Pre-fill vendor only when all items share the same vendor
         const vendorIds = [...new Set(cartItems.map((i) => i.vendorId).filter(Boolean))];
         if (vendorIds.length === 1) initialVendorId = vendorIds[0];
       }
@@ -50,39 +49,18 @@ export default async function NewPoPage({ searchParams }: Props) {
   }
 
   const [vessels, sites, leafAccounts, vendors] = await Promise.all([
-    db.vessel.findMany({ where: { isActive: true }, orderBy: { name: "asc" }, select: { id: true, name: true, code: true } }),
-    db.site.findMany({ where: { isActive: true }, orderBy: { name: "asc" }, select: { id: true, name: true, code: true } }),
+    db.vessel.findMany({ where: { isActive: true }, orderBy: { name: "asc" }, select: { id: true, name: true, code: true, siteId: true } }),
+    db.site.findMany({ where: { isActive: true }, orderBy: { name: "asc" }, select: { id: true, name: true } }),
     db.account.findMany({
       where: { isActive: true, children: { none: {} } },
       orderBy: { code: "asc" },
-      select: {
-        id: true, code: true, name: true,
-        parent: {
-          select: {
-            name: true, code: true,
-            parent: { select: { name: true, code: true } },
-          },
-        },
-      },
+      select: { id: true, code: true, name: true, parent: { select: { name: true, code: true, parent: { select: { name: true, code: true } } } } },
     }),
     db.vendor.findMany({ where: { isActive: true }, orderBy: { name: "asc" } }),
   ]);
 
-  // Build grouped account list for optgroups: "TOP CAT > Sub Cat" → items
-  const accountGroupMap = new Map<string, typeof leafAccounts>();
-  for (const a of leafAccounts) {
-    const subLabel = a.parent ? `${a.parent.code} — ${a.parent.name}` : "Uncategorised";
-    const topLabel = a.parent?.parent ? `${a.parent.parent.name} › ` : "";
-    const groupKey = `${topLabel}${subLabel}`;
-    if (!accountGroupMap.has(groupKey)) accountGroupMap.set(groupKey, []);
-    accountGroupMap.get(groupKey)!.push(a);
-  }
-  const accounts = Array.from(accountGroupMap.entries()).map(([group, items]) => ({ group, items }));
-
-  const costCentres: CostCentreOption[] = [
-    ...vessels.map((v) => ({ ref: `v:${v.id}` as const, label: `${v.code} — ${v.name}`, group: "Vessels" as const })),
-    ...sites.map((s) => ({ ref: `s:${s.id}` as const, label: `${s.code} — ${s.name}`, group: "Sites" as const })),
-  ];
+  const costCentres = buildCostCentreGroups(vessels, sites);
+  const accounts = buildAccountGroups(leafAccounts);
 
   return (
     <div className="max-w-6xl">
@@ -92,7 +70,14 @@ export default async function NewPoPage({ searchParams }: Props) {
           Fill in the details below. You can save as draft or submit directly for approval.
         </p>
       </div>
-      <NewPoForm costCentres={costCentres} accounts={accounts} vendors={vendors} initialLineItems={initialLineItems} initialVendorId={initialVendorId} initialCostCentreRef={initialCostCentreRef} />
+      <NewPoForm
+        costCentres={costCentres}
+        accounts={accounts}
+        vendors={vendors}
+        initialLineItems={initialLineItems}
+        initialVendorId={initialVendorId}
+        initialCostCentreRef={initialCostCentreRef}
+      />
     </div>
   );
 }

App/components/po/po-line-items-editor.tsx

@@ -4,6 +4,8 @@ import { useState, useEffect, useRef } from "react";
 import { Plus, Trash2 } from "lucide-react";
 import { formatCurrency } from "@/lib/utils";
 import type { LineItemInput } from "@/lib/validations/po";
+import { SearchableSelect } from "@/components/ui/searchable-select";
+import type { AccountGroup } from "@/app/(portal)/po/new/new-po-form";
 
 const UOM_OPTIONS = [
   { value: "pc",   label: "pc — Piece" },
@@ -44,8 +46,9 @@ interface Props {
   originalItemsLabel?: string;
   /** When true, show per-row account selector */
   multiAccount?: boolean;
-  accounts?: AccountOption[];
-  /** The PO-level default account id — pre-selected in each row dropdown */
+  /** Grouped accounts for the searchable per-row selector */
+  accounts?: AccountGroup[];
+  /** The PO-level default account id — pre-selected in each row */
   defaultAccountId?: string;
 }
 
@@ -246,7 +249,9 @@ export function LineItemsEditor({
     updateRows(rows.filter((_, i) => i !== index));
   }
 
-  const accountMap = Object.fromEntries(accounts.map((a) => [a.id, a]));
+  const accountMap = Object.fromEntries(
+    (accounts ?? []).flatMap((g) => g.items).map((a) => [a.id, a])
+  );
 
   // ── Read-only view ───────────────────────────────────────────────────────────
   if (readOnly) {
@@ -363,7 +368,7 @@ export function LineItemsEditor({
           <tbody className="divide-y divide-neutral-100">
             {rows.map((row, i) => {
               const taxableAmt = (parseFloat(row.quantity) || 0) * (parseFloat(row.unitPrice) || 0);
-              const gstR = parseFloat(row.gstRate) || 0.18;
+              const gstR = row.gstRate !== "" && row.gstRate != null ? parseFloat(row.gstRate) : 0.18;
               return (
                 <tr key={i}>
                   <td className="py-2 pr-4">
@@ -424,16 +429,15 @@ export function LineItemsEditor({
                     </select>
                   </td>
                   {multiAccount && (
-                    <td className="py-2 pl-4">
-                      <select
+                    <td className="py-2 pl-4 min-w-[200px]">
+                      <SearchableSelect
+                        name={`__account_row_${i}`}
                         value={row.accountId ?? defaultAccountId ?? ""}
-                        onChange={(e) => update(i, "accountId", e.target.value)}
-                        className="w-36 rounded border border-neutral-200 px-2 py-1.5 text-sm focus:border-primary-500 focus:outline-none"
-                      >
-                        {accounts.map((a) => (
-                          <option key={a.id} value={a.id}>{a.name} ({a.code})</option>
-                        ))}
-                      </select>
+                        onChange={(v) => update(i, "accountId", v)}
+                        groups={accounts ?? []}
+                        placeholder="Select code…"
+                        size="compact"
+                      />
                     </td>
                   )}
                   <td className="py-2 pl-4 text-right text-sm">

App/components/ui/searchable-select.tsx

@@ -0,0 +1,201 @@
+"use client";
+
+import { useState, useRef, useEffect, useCallback } from "react";
+import { ChevronDown, Search, X } from "lucide-react";
+import type { AccountGroup } from "@/app/(portal)/po/new/new-po-form";
+
+interface Props {
+  name: string;
+  value: string;
+  onChange: (value: string) => void;
+  groups: AccountGroup[];
+  placeholder?: string;
+  required?: boolean;
+  /** "default" for the main PO field, "compact" for the per-line-item table cell */
+  size?: "default" | "compact";
+}
+
+export function SearchableSelect({
+  name,
+  value,
+  onChange,
+  groups,
+  placeholder = "Select accounting code…",
+  required,
+  size = "default",
+}: Props) {
+  const [open, setOpen] = useState(false);
+  const [query, setQuery] = useState("");
+  const containerRef = useRef<HTMLDivElement>(null);
+  const searchRef = useRef<HTMLInputElement>(null);
+
+  // Close on outside click / Escape
+  useEffect(() => {
+    if (!open) return;
+    function handleKey(e: KeyboardEvent) {
+      if (e.key === "Escape") { setOpen(false); setQuery(""); }
+    }
+    function handleClick(e: MouseEvent) {
+      if (containerRef.current && !containerRef.current.contains(e.target as Node)) {
+        setOpen(false);
+        setQuery("");
+      }
+    }
+    document.addEventListener("keydown", handleKey);
+    document.addEventListener("mousedown", handleClick);
+    return () => {
+      document.removeEventListener("keydown", handleKey);
+      document.removeEventListener("mousedown", handleClick);
+    };
+  }, [open]);
+
+  // Auto-focus search input when opened
+  useEffect(() => {
+    if (open) searchRef.current?.focus();
+  }, [open]);
+
+  // Find the display label for the current value
+  const selectedItem = groups.flatMap((g) => g.items).find((i) => i.id === value);
+  const selectedLabel = selectedItem ? `${selectedItem.code} — ${selectedItem.name}` : "";
+
+  // Filter by query (code or name, case-insensitive)
+  const q = query.trim().toLowerCase();
+  const filtered = q
+    ? groups
+        .map((g) => ({
+          ...g,
+          items: g.items.filter(
+            (i) =>
+              i.code.toLowerCase().includes(q) ||
+              i.name.toLowerCase().includes(q)
+          ),
+        }))
+        .filter((g) => g.items.length > 0)
+    : groups;
+
+  const handleSelect = useCallback(
+    (id: string) => {
+      onChange(id);
+      setOpen(false);
+      setQuery("");
+    },
+    [onChange]
+  );
+
+  const handleClear = useCallback(
+    (e: React.MouseEvent) => {
+      e.stopPropagation();
+      onChange("");
+    },
+    [onChange]
+  );
+
+  const isCompact = size === "compact";
+
+  return (
+    <div ref={containerRef} className="relative w-full">
+      {/* Hidden input for form submission */}
+      <input type="hidden" name={name} value={value} />
+      {required && !value && (
+        /* Invisible trick to trigger native "required" validation on submit */
+        <input
+          tabIndex={-1}
+          required
+          value={value}
+          onChange={() => {}}
+          className="absolute opacity-0 w-0 h-0 pointer-events-none"
+          aria-hidden
+        />
+      )}
+
+      {/* Trigger */}
+      <button
+        type="button"
+        onClick={() => setOpen((v) => !v)}
+        className={`w-full flex items-center justify-between gap-2 rounded-lg border
+          ${open ? "border-primary-500 ring-2 ring-primary-500/20" : "border-neutral-300"}
+          bg-white text-left transition-colors
+          focus:border-primary-500 focus:outline-none focus:ring-2 focus:ring-primary-500/20
+          ${isCompact ? "px-2 py-1.5 text-xs" : "px-3 py-2.5 text-sm"}`}
+      >
+        <span
+          className={`truncate flex-1 min-w-0 ${selectedLabel ? "text-neutral-900" : "text-neutral-400"}`}
+        >
+          {selectedLabel || placeholder}
+        </span>
+        <span className="flex items-center gap-1 shrink-0">
+          {value && (
+            <span
+              role="button"
+              tabIndex={0}
+              onClick={handleClear}
+              onKeyDown={(e) => e.key === "Enter" && handleClear(e as unknown as React.MouseEvent)}
+              className="text-neutral-300 hover:text-neutral-500 transition-colors"
+            >
+              <X className={isCompact ? "h-3 w-3" : "h-4 w-4"} />
+            </span>
+          )}
+          <ChevronDown
+            className={`text-neutral-400 transition-transform ${open ? "rotate-180" : ""} ${isCompact ? "h-3 w-3" : "h-4 w-4"}`}
+          />
+        </span>
+      </button>
+
+      {/* Dropdown panel */}
+      {open && (
+        <div
+          className={`absolute z-50 left-0 right-0 mt-1 rounded-lg border border-neutral-200 bg-white shadow-xl
+            ${isCompact ? "min-w-[280px]" : ""}`}
+          style={{ maxWidth: isCompact ? "360px" : undefined }}
+        >
+          {/* Search input */}
+          <div className="flex items-center gap-2 p-2 border-b border-neutral-100">
+            <Search className="h-4 w-4 text-neutral-400 shrink-0" />
+            <input
+              ref={searchRef}
+              type="text"
+              value={query}
+              onChange={(e) => setQuery(e.target.value)}
+              placeholder="Type code or name…"
+              className="flex-1 text-sm outline-none placeholder:text-neutral-400"
+            />
+            {query && (
+              <button type="button" onClick={() => setQuery("")} className="text-neutral-300 hover:text-neutral-500">
+                <X className="h-3.5 w-3.5" />
+              </button>
+            )}
+          </div>
+
+          {/* Options */}
+          <div className="max-h-64 overflow-y-auto overscroll-contain">
+            {filtered.length === 0 ? (
+              <p className="px-3 py-5 text-sm text-center text-neutral-400">No codes match "{query}"</p>
+            ) : (
+              filtered.map((group) => (
+                <div key={group.group}>
+                  {/* Group header */}
+                  <div className="sticky top-0 px-3 py-1 text-xs font-semibold text-neutral-500 bg-neutral-50 border-b border-neutral-100">
+                    {group.group}
+                  </div>
+                  {/* Items */}
+                  {group.items.map((item) => (
+                    <button
+                      key={item.id}
+                      type="button"
+                      onMouseDown={(e) => { e.preventDefault(); handleSelect(item.id); }}
+                      className={`w-full text-left flex items-baseline gap-2.5 px-3 py-2 text-sm hover:bg-primary-50 transition-colors
+                        ${value === item.id ? "bg-primary-50 text-primary-700 font-medium" : "text-neutral-800"}`}
+                    >
+                      <span className="font-mono text-xs text-neutral-400 shrink-0 w-14">{item.code}</span>
+                      <span className="flex-1 leading-snug">{item.name}</span>
+                    </button>
+                  ))}
+                </div>
+              ))
+            )}
+          </div>
+        </div>
+      )}
+    </div>
+  );
+}

App/lib/cost-centre-groups.ts

@@ -0,0 +1,59 @@
+import type { CostCentreGroup } from "@/app/(portal)/po/new/new-po-form";
+
+type VesselLike = { id: string; name: string; code: string; siteId: string | null };
+type SiteLike   = { id: string; name: string };
+
+/**
+ * Builds the grouped cost-centre list used by PO form dropdowns.
+ * Each group = one site (as an optgroup), with the site itself as a selectable
+ * option followed by its vessels.
+ * Vessels with no site appear under an "Unassigned Vessels" group at the end.
+ */
+export function buildCostCentreGroups(
+  vessels: VesselLike[],
+  sites: SiteLike[]
+): CostCentreGroup[] {
+  const groups: CostCentreGroup[] = sites.map((s) => ({
+    siteId: s.id,
+    siteName: s.name,
+    siteRef: `s:${s.id}`,
+    vessels: vessels
+      .filter((v) => v.siteId === s.id)
+      .map((v) => ({ ref: `v:${v.id}`, label: `${v.code} — ${v.name}` })),
+  }));
+
+  const unassigned = vessels.filter((v) => !v.siteId);
+  if (unassigned.length > 0) {
+    groups.push({
+      siteId: null,
+      siteName: "Unassigned Vessels",
+      siteRef: null,
+      vessels: unassigned.map((v) => ({ ref: `v:${v.id}`, label: `${v.code} — ${v.name}` })),
+    });
+  }
+
+  return groups;
+}
+
+/**
+ * Builds grouped accounting codes for the SearchableSelect component.
+ * Only returns leaf items (no children), grouped by sub-category.
+ */
+export function buildAccountGroups(
+  leafAccounts: {
+    id: string;
+    code: string;
+    name: string;
+    parent: { name: string; code: string; parent: { name: string; code: string } | null } | null;
+  }[]
+) {
+  const map = new Map<string, { id: string; code: string; name: string }[]>();
+  for (const a of leafAccounts) {
+    const subLabel = a.parent ? `${a.parent.code} — ${a.parent.name}` : "Uncategorised";
+    const topLabel = a.parent?.parent ? `${a.parent.parent.name} › ` : "";
+    const key = `${topLabel}${subLabel}`;
+    if (!map.has(key)) map.set(key, []);
+    map.get(key)!.push({ id: a.id, code: a.code, name: a.name });
+  }
+  return Array.from(map.entries()).map(([group, items]) => ({ group, items }));
+}