chore(work-orders): merge dev into Add-On indicator branch

Integrate SH-189 duplicate WO dialog with SH-184 Add-On indicator:
preserve remote duplicate check, AddOnPill, and inline override toggle.

src/app/(protected)/workorders/_components/list/duplicate-wo-number-dialog.tsx

@@ -0,0 +1,45 @@
+import { Button, Dialog, DialogActions, DialogContent, DialogTitle } from "@mui/material";
+import { Text } from "@/components/ui/text";
+import type { WorkOrderTableRow } from "@/domain/work-orders/types/work-order-table-row";
+
+type DuplicateWoNumberDialogProps = {
+  open: boolean;
+  existing: WorkOrderTableRow | null;
+  onDismiss: () => void;
+  onViewExisting: (row: WorkOrderTableRow) => void;
+};
+
+export function DuplicateWoNumberDialog({
+  open,
+  existing,
+  onDismiss,
+  onViewExisting,
+}: DuplicateWoNumberDialogProps) {
+  const woNumber = existing?.woNumber ?? "";
+
+  return (
+    <Dialog open={open} onClose={onDismiss} aria-labelledby="duplicate-wo-number-dialog-title">
+      <DialogTitle id="duplicate-wo-number-dialog-title">Duplicate Work Order Number</DialogTitle>
+      <DialogContent>
+        <Text variant="body">
+          Work order number {woNumber} is already assigned to another work order. View the existing
+          record or dismiss to keep editing.
+        </Text>
+      </DialogContent>
+      <DialogActions>
+        <Button onClick={onDismiss}>Dismiss</Button>
+        <Button
+          variant="contained"
+          disabled={existing == null}
+          onClick={() => {
+            if (existing != null) {
+              onViewExisting(existing);
+            }
+          }}
+        >
+          View existing
+        </Button>
+      </DialogActions>
+    </Dialog>
+  );
+}

src/app/(protected)/workorders/_components/list/table/cells/editable-wo-number-cell.tsx

@@ -1,46 +1,32 @@
 import { useEffect, useState } from "react";
-
 import { toast } from "react-toastify";
-
+import { workOrdersApi } from "@/domain/work-orders/api/work-orders-api";
 import type { WorkOrderTableRow } from "@/domain/work-orders/types/work-order-table-row";
-
+import { findDuplicateWoNumberRow } from "@/domain/work-orders/utils/find-duplicate-wo-number-row";
 import { EditableWONumberInput } from "./editable-wo-number-input";
 import { HighlightText } from "./highlight-text";
 
 type EditableWONumberCellProps = {
   value: string;
-
   rescheduleCount: number;
-
   carriedOver?: number;
-
   isAddOn?: boolean;
-
   q?: string;
-
   currentId: string | number;
-
   allOrders: WorkOrderTableRow[];
-
   onSave: (v: string) => void;
-
   onDuplicateFound?: (existing: WorkOrderTableRow) => void;
 };
 
 function CounterPill({ label, count }: { label: string; count: number }) {
-  if (count < 2) {
-    return null;
-  }
-
+  if (count < 2) return null;
   return (
     <span
       title={label}
       className="inline-flex h-[18px] items-center rounded px-1.5 text-[10px] font-semibold"
       style={{
         background: "var(--color-bg-muted)",
-
         color: "var(--color-text-secondary)",
-
         border: "1px solid var(--color-border)",
       }}
     >
@@ -68,91 +54,78 @@ function AddOnPill({ when }: { when: boolean }) {
   );
 }
 
+async function resolveDuplicateWoNumber(
+  draft: string,
+  allOrders: WorkOrderTableRow[],
+  currentId: string | number,
+) {
+  const local = findDuplicateWoNumberRow(draft, allOrders, currentId);
+  const remote = local ?? (await workOrdersApi.findByWoNumber(draft));
+  return remote && String(remote.id) !== String(currentId) ? remote : undefined;
+}
+
 export function EditableWONumberCell({
   value,
-
   rescheduleCount,
-
   carriedOver = 0,
-
   isAddOn = false,
-
   q,
-
   currentId,
-
   allOrders,
-
   onSave,
-
   onDuplicateFound,
 }: EditableWONumberCellProps) {
   const [editing, setEditing] = useState(false);
-
   const [draft, setDraft] = useState(value);
+  const [isChecking, setIsChecking] = useState(false);
 
   useEffect(() => {
-    if (!editing) {
-      setDraft(value);
-    }
+    if (!editing) setDraft(value);
   }, [value, editing]);
 
-  const findDuplicate = (d: string) =>
-    allOrders.find((o) => o.woNumber === d && String(o.id) !== String(currentId));
-
   const commit = () => {
-    if (draft === value) {
+    if (draft === value || isChecking) {
       setEditing(false);
-
       return;
     }
-
     if (draft.length !== 11) {
       toast("Work order number must be exactly 11 digits");
-
       return;
     }
-
-    const duplicate = findDuplicate(draft);
-
-    if (duplicate) {
-      onDuplicateFound?.(duplicate);
-
-      setDraft(value);
-
-      setEditing(false);
-
-      return;
-    }
-
-    onSave(draft);
-
-    setEditing(false);
+    setIsChecking(true);
+    void (async () => {
+      try {
+        const duplicate = await resolveDuplicateWoNumber(draft, allOrders, currentId);
+        if (duplicate) {
+          if (onDuplicateFound) {
+            onDuplicateFound(duplicate);
+          } else {
+            toast.error(`WO #${duplicate.woNumber} is already assigned to another work order.`);
+          }
+          setDraft(value);
+          return;
+        }
+        onSave(draft);
+      } catch {
+        toast.error("Unable to verify the work order number. Please try again.");
+      } finally {
+        setIsChecking(false);
+        setEditing(false);
+      }
+    })();
   };
 
   const cancel = () => {
     setDraft(value);
-
     setEditing(false);
   };
 
   const handleBlur = () => {
+    if (isChecking) return;
     if (draft !== value && draft.length === 11) {
-      const duplicate = findDuplicate(draft);
-
-      if (duplicate) {
-        onDuplicateFound?.(duplicate);
-
-        setDraft(value);
-
-        setEditing(false);
-
-        return;
-      }
-
-      onSave(draft);
+      commit();
+      return;
     }
-
     setEditing(false);
   };
 
@@ -164,6 +137,7 @@ export function EditableWONumberCell({
         <EditableWONumberInput
           draft={draft}
           invalid={invalid}
+          isChecking={isChecking}
           onChange={setDraft}
           onCommit={commit}
           onBlur={handleBlur}
@@ -173,30 +147,22 @@ export function EditableWONumberCell({
         <span
           onClick={(e) => {
             e.stopPropagation();
-
             setEditing(true);
           }}
           className="inline-block cursor-text font-mono transition-colors hover:bg-[var(--color-bg-muted)]"
           style={{
             fontSize: 13,
-
             fontWeight: 700,
-
             color: value ? "var(--foreground)" : "var(--color-text-muted)",
-
             borderRadius: 4,
-
             padding: "2px 4px",
           }}
         >
           {value ? <HighlightText text={value} q={q} /> : "-"}
         </span>
       )}
-
       <AddOnPill when={isAddOn} />
-
       <CounterPill label="Reschedules" count={rescheduleCount} />
-
       <CounterPill label="Carried over" count={carriedOver} />
     </div>
   );

src/app/(protected)/workorders/_components/list/table/cells/editable-wo-number-input.tsx

@@ -1,6 +1,7 @@
 type EditableWONumberInputProps = {
   draft: string;
   invalid: boolean;
+  isChecking?: boolean;
   onChange: (value: string) => void;
   onCommit: () => void;
   onBlur?: () => void;
@@ -10,6 +11,7 @@ type EditableWONumberInputProps = {
 export function EditableWONumberInput({
   draft,
   invalid,
+  isChecking = false,
   onChange,
   onCommit,
   onBlur,
@@ -18,6 +20,7 @@ export function EditableWONumberInput({
   return (
     <input
       autoFocus
+      disabled={isChecking}
       inputMode="numeric"
       value={draft}
       onChange={(event) => onChange(event.target.value.replace(/\D/g, "").slice(0, 11))}

src/app/(protected)/workorders/_components/list/table/use-wo-table-inline-create.ts

@@ -0,0 +1,58 @@
+import { useState } from "react";
+import { toast } from "react-toastify";
+import type { LocationOption, WorkOrderUser } from "@/domain/work-orders/types/work-order";
+import type { WorkOrderTableRow } from "@/domain/work-orders/types/work-order-table-row";
+import { workOrdersApi } from "@/domain/work-orders/api/work-orders-api";
+import { useCreateWorkOrderFromWizard } from "@/domain/work-orders/use-cases/use-create-work-order-from-wizard";
+import { findDuplicateWoNumberRow } from "@/domain/work-orders/utils/find-duplicate-wo-number-row";
+import type { ReturnTypeOfUseWorkOrdersTableData } from "./wo-table-types";
+import { buildInlineDraftCreateInput } from "./build-inline-draft-create-input";
+
+type UseWoTableInlineCreateArgs = {
+  tableData: ReturnTypeOfUseWorkOrdersTableData;
+  users: WorkOrderUser[];
+  sites: LocationOption[];
+  onDuplicateFound: (row: WorkOrderTableRow) => void;
+};
+
+export function useWoTableInlineCreate({
+  tableData,
+  users,
+  sites,
+  onDuplicateFound,
+}: UseWoTableInlineCreateArgs) {
+  const [isCheckingInlineDuplicate, setIsCheckingInlineDuplicate] = useState(false);
+  const createMutation = useCreateWorkOrderFromWizard(() => {
+    tableData.cancelDraft();
+  });
+
+  const handleInlineSave = () => {
+    void (async () => {
+      const draftSnapshot = tableData.draft;
+      const woNumber = draftSnapshot.woNumber.trim();
+      if (woNumber) {
+        setIsCheckingInlineDuplicate(true);
+        try {
+          const duplicate =
+            findDuplicateWoNumberRow(woNumber, tableData.rows, "draft") ??
+            (await workOrdersApi.findByWoNumber(woNumber));
+          if (duplicate && String(duplicate.id) !== "draft") {
+            onDuplicateFound(duplicate);
+            return;
+          }
+        } catch {
+          toast.error("Unable to verify the work order number. Please try again.");
+          return;
+        } finally {
+          setIsCheckingInlineDuplicate(false);
+        }
+      }
+      createMutation.mutate(buildInlineDraftCreateInput(tableData.draft, users, sites));
+    })();
+  };
+
+  return {
+    handleInlineSave,
+    saving: createMutation.isPending || isCheckingInlineDuplicate,
+  };
+}

src/app/(protected)/workorders/_components/list/table/use-wo-table-row-handlers.ts

@@ -19,6 +19,7 @@ type UseWoTableRowHandlersOptions = {
   onOpenMedia: (row: WorkOrderTableRow) => void;
   onPatch: (id: string | number, patch: WorkOrderTablePatch) => void;
   onScheduleHighlight: (id: string | number | null) => void;
+  onDuplicateFound?: (existing: WorkOrderTableRow) => void;
 };
 
 export function useWoTableRowHandlers({
@@ -30,6 +31,7 @@ export function useWoTableRowHandlers({
   onOpenMedia,
   onPatch,
   onScheduleHighlight,
+  onDuplicateFound,
 }: UseWoTableRowHandlersOptions): WoTableRowHandlers {
   const {
     dragState: dragStateRef,
@@ -97,8 +99,7 @@ export function useWoTableRowHandlers({
         });
       },
       onDuplicateFound: (existing: WorkOrderTableRow) => {
-        tableData.setSelectedId(existing.id);
-        onOpenSlideOver(existing, false);
+        onDuplicateFound?.(existing);
       },
       onOpenSlideOver: (row: WorkOrderTableRow) => onOpenSlideOver(row, false),
       onPastDueAttempt: (id: string | number) => onScheduleHighlight(id),
@@ -138,6 +139,7 @@ export function useWoTableRowHandlers({
       onOpenMedia,
       onPatch,
       onScheduleHighlight,
+      onDuplicateFound,
     ],
   );
 }

src/app/(protected)/workorders/_components/list/table/wo-table-inline-identity-cells.tsx

@@ -1,6 +1,9 @@
 import type { RefObject } from "react";
 import type { LocationOption } from "@/domain/work-orders/types/work-order";
-import type { WorkOrderTableDraft } from "@/domain/work-orders/types/work-order-table-row";
+import type {
+  WorkOrderTableDraft,
+  WorkOrderTableRow,
+} from "@/domain/work-orders/types/work-order-table-row";
 import { AddOnOverrideToggle } from "./add-on-override-toggle";
 import { EditableWONumberCell } from "./cells/editable-wo-number-cell";
 import { SiteCell } from "./cells/site-cell";
@@ -17,6 +20,7 @@ type WoTableInlineIdentityCellsProps = {
   siteError: string;
   woShowError: boolean;
   onPatch: (patch: Partial<WorkOrderTableDraft>) => void;
+  onDuplicateFound?: (existing: WorkOrderTableRow) => void;
 };
 
 export function WoTableInlineIdentityCells({
@@ -30,6 +34,7 @@ export function WoTableInlineIdentityCells({
   siteError,
   woShowError,
   onPatch,
+  onDuplicateFound,
 }: WoTableInlineIdentityCellsProps) {
   const isUnscheduled = Boolean(!draft.scheduledOn && !draft.targetWeek);
 
@@ -79,6 +84,7 @@ export function WoTableInlineIdentityCells({
               currentId="draft"
               allOrders={allRows as never[]}
               onSave={(v) => onPatch({ woNumber: v })}
+              onDuplicateFound={onDuplicateFound}
             />
             <AddOnOverrideToggle
               checked={draft.isAddOnOverride}

src/app/(protected)/workorders/_components/list/table/wo-table-inline-row-cells.tsx

@@ -4,7 +4,10 @@ import type {
   VendorDropdownItem,
   WorkOrderUser,
 } from "@/domain/work-orders/types/work-order";
-import type { WorkOrderTableDraft } from "@/domain/work-orders/types/work-order-table-row";
+import type {
+  WorkOrderTableDraft,
+  WorkOrderTableRow,
+} from "@/domain/work-orders/types/work-order-table-row";
 import { AssignedToCell } from "./cells/assigned-to-cell";
 import { ApptTimeCell } from "./cells/appt-time-cell";
 import { DateCell } from "./cells/date-cell";
@@ -31,6 +34,7 @@ type WoTableInlineRowCellsProps = {
   siteError: string;
   woShowError: boolean;
   onPatch: (patch: Partial<WorkOrderTableDraft>) => void;
+  onDuplicateFound?: (existing: WorkOrderTableRow) => void;
 };
 
 function InlineMutedDashCell() {
@@ -106,6 +110,7 @@ export function WoTableInlineRowCells({
   siteError,
   woShowError,
   onPatch,
+  onDuplicateFound,
 }: WoTableInlineRowCellsProps) {
   const draftRow = toInlineDraftRow(draft);
 
@@ -122,6 +127,7 @@ export function WoTableInlineRowCells({
         siteError={siteError}
         woShowError={woShowError}
         onPatch={onPatch}
+        onDuplicateFound={onDuplicateFound}
       />
 
       <td className="group/cell" style={{ padding: "0 14px" }}>

src/app/(protected)/workorders/_components/list/table/wo-table-inline-row.tsx

@@ -6,7 +6,10 @@ import type {
   VendorDropdownItem,
   WorkOrderUser,
 } from "@/domain/work-orders/types/work-order";
-import type { WorkOrderTableDraft } from "@/domain/work-orders/types/work-order-table-row";
+import type {
+  WorkOrderTableDraft,
+  WorkOrderTableRow,
+} from "@/domain/work-orders/types/work-order-table-row";
 import { UNSCHEDULED_DAY_KEY } from "@/domain/work-orders/types/work-order-table-row";
 import {
   draftHasScheduleDate,
@@ -32,6 +35,7 @@ type WoTableInlineRowProps = {
   onChange: (draft: WorkOrderTableDraft) => void;
   onSave: () => void;
   onCancel: () => void;
+  onDuplicateFound?: (existing: WorkOrderTableRow) => void;
 };
 
 const PRE_SCHEDULE = new Set(["Incomplete", "Pending", ""]);
@@ -60,6 +64,7 @@ export function WoTableInlineRow({
   onChange,
   onSave,
   onCancel,
+  onDuplicateFound,
 }: WoTableInlineRowProps) {
   const weekDefault = draftDayKey === UNSCHEDULED_DAY_KEY;
   const missing = getInlineCreateMissing(draft);
@@ -127,6 +132,7 @@ export function WoTableInlineRow({
         siteError={inlineCreateSiteError(missing)}
         woShowError={woShowError}
         onPatch={patch}
+        onDuplicateFound={onDuplicateFound}
       />
 
       <td style={{ padding: "0 4px" }}>

src/app/(protected)/workorders/_components/list/table/wo-table.tsx

@@ -9,11 +9,11 @@ import type {
   WorkOrderTablePatch,
   WorkOrderTableRow,
 } from "@/domain/work-orders/types/work-order-table-row";
-import { useCreateWorkOrderFromWizard } from "@/domain/work-orders/use-cases/use-create-work-order-from-wizard";
+import { DuplicateWoNumberDialog } from "@/app/(protected)/workorders/_components/list/duplicate-wo-number-dialog";
 import { WoTableSkeleton } from "@/app/(protected)/workorders/_components/loading/wo-table-skeleton";
 import type { ReturnTypeOfUseWorkOrdersTableData } from "./wo-table-types";
-import { buildInlineDraftCreateInput } from "./build-inline-draft-create-input";
 import { buildSitePlaceLookups, resolveSitePlace } from "./site-place-lookup";
+import { useWoTableInlineCreate } from "./use-wo-table-inline-create";
 import { useWoTableRowHandlers } from "./use-wo-table-row-handlers";
 import { WoTableBody } from "./wo-table-body";
 import { WoTableHead } from "./wo-table-head";
@@ -55,10 +55,14 @@ export function WoTable({
   onPatch,
 }: WoTableProps) {
   const [dueDateHighlightId, setDueDateHighlightId] = useState<string | number | null>(null);
+  const [duplicateRow, setDuplicateRow] = useState<WorkOrderTableRow | null>(null);
   const { data: locationSites = [] } = useLocationSites();
   const sitePlaceLookups = useMemo(() => buildSitePlaceLookups(locationSites), [locationSites]);
-  const createMutation = useCreateWorkOrderFromWizard(() => {
-    tableData.cancelDraft();
+  const { handleInlineSave, saving } = useWoTableInlineCreate({
+    tableData,
+    users,
+    sites,
+    onDuplicateFound: setDuplicateRow,
   });
 
   const handlers = useWoTableRowHandlers({
@@ -70,6 +74,7 @@ export function WoTable({
     onOpenMedia,
     onPatch,
     onScheduleHighlight: setDueDateHighlightId,
+    onDuplicateFound: setDuplicateRow,
   });
 
   const renderRow = (row: WorkOrderTableRow, forceScheduleHighlight = false) => (
@@ -107,12 +112,11 @@ export function WoTable({
         vendors={vendors}
         pmTypes={pmTypes}
         allRows={tableData.rows}
-        saving={createMutation.isPending}
+        saving={saving}
         onChange={tableData.setDraft}
-        onSave={() =>
-          createMutation.mutate(buildInlineDraftCreateInput(tableData.draft, users, sites))
-        }
+        onSave={handleInlineSave}
         onCancel={tableData.cancelDraft}
+        onDuplicateFound={setDuplicateRow}
       />
     );
 
@@ -151,21 +155,33 @@ export function WoTable({
   }
 
   return (
-    <WoTableShell>
-      <table
-        style={{
-          width: "100%",
-          minWidth: WO_TABLE_MIN_WIDTH,
-          borderCollapse: "collapse",
+    <>
+      <WoTableShell>
+        <table
+          style={{
+            width: "100%",
+            minWidth: WO_TABLE_MIN_WIDTH,
+            borderCollapse: "collapse",
+          }}
+        >
+          <WoTableHead />
+          <WoTableBody
+            tableData={tableData}
+            renderRow={renderRow}
+            renderInlineRow={renderInlineRow}
+          />
+        </table>
+      </WoTableShell>
+
+      <DuplicateWoNumberDialog
+        open={duplicateRow != null}
+        existing={duplicateRow}
+        onDismiss={() => setDuplicateRow(null)}
+        onViewExisting={(row) => {
+          setDuplicateRow(null);
+          onOpenSlideOver(row, false);
         }}
-      >
-        <WoTableHead />
-        <WoTableBody
-          tableData={tableData}
-          renderRow={renderRow}
-          renderInlineRow={renderInlineRow}
-        />
-      </table>
-    </WoTableShell>
+      />
+    </>
   );
 }

src/app/(protected)/workorders/_components/list/work-orders-list-wizard.tsx

@@ -0,0 +1,32 @@
+import { NewWoWizard } from "@/app/(protected)/workorders/_components/wizard/new-wo-wizard";
+import type { WorkOrderUser } from "@/domain/work-orders/types/work-order";
+import type { WorkOrderTableRow } from "@/domain/work-orders/types/work-order-table-row";
+
+type WorkOrdersListWizardProps = {
+  open: boolean;
+  onOpenChange: (open: boolean) => void;
+  users: WorkOrderUser[];
+  rows: WorkOrderTableRow[];
+  onViewExisting: (row: WorkOrderTableRow) => void;
+};
+
+export function WorkOrdersListWizard({
+  open,
+  onOpenChange,
+  users,
+  rows,
+  onViewExisting,
+}: WorkOrdersListWizardProps) {
+  return (
+    <NewWoWizard
+      open={open}
+      onOpenChange={onOpenChange}
+      users={users}
+      existingRows={rows}
+      onViewExistingWo={(row) => {
+        onOpenChange(false);
+        onViewExisting(row);
+      }}
+    />
+  );
+}

src/app/(protected)/workorders/_components/wizard/new-wo-wizard.tsx

@@ -1,38 +1,23 @@
-import { useEffect, useMemo, useState } from "react";
 import { Dialog } from "@mui/material";
 import { dialogBlurBackdropSlotProps } from "@/components/ui/dialog-blur-backdrop";
 import { Text } from "@/components/ui/text";
-import { useDropdownOptionsByCategory } from "@/domain/settings/dropdown-options/use-cases/use-dropdown-options-by-category";
-import { isWoWizardMockEnabled } from "@/domain/work-orders/mocks/is-wo-wizard-mock-enabled";
-import {
-  getMockWoWizardLocationDetail,
-  MOCK_WO_WIZARD_LOCATIONS,
-  MOCK_WO_WIZARD_SERVICES,
-  MOCK_WO_WIZARD_USERS,
-  MOCK_WO_WIZARD_VENDORS,
-} from "@/domain/work-orders/mocks/wo-wizard-mock-data";
+import { DuplicateWoNumberDialog } from "@/app/(protected)/workorders/_components/list/duplicate-wo-number-dialog";
 import type { WorkOrderUser } from "@/domain/work-orders/types/work-order";
-import {
-  EMPTY_WIZARD_DRAFT,
-  WIZARD_STEPS,
-  type WorkOrderWizardDraft,
-} from "@/domain/work-orders/types/work-order-wizard";
-import { useLocationDetail } from "@/domain/locations/use-cases/use-location-detail";
-import {
-  useWorkOrderLocations,
-  useWorkOrderVendors,
-} from "@/domain/work-orders/use-cases/use-work-order-detail";
-import { useCreateWorkOrderFromWizard } from "@/domain/work-orders/use-cases/use-create-work-order-from-wizard";
+import type { WorkOrderTableRow } from "@/domain/work-orders/types/work-order-table-row";
+import { WIZARD_STEPS } from "@/domain/work-orders/types/work-order-wizard";
 import { WizardFooter } from "@/app/(protected)/workorders/_components/wizard/wizard-footer";
 import { WizardSidebar } from "@/app/(protected)/workorders/_components/wizard/wizard-sidebar";
 import { WizardStepLocationService } from "@/app/(protected)/workorders/_components/wizard/wizard-step-location-service";
 import { WizardStepTypeSchedule } from "@/app/(protected)/workorders/_components/wizard/wizard-step-type-schedule";
 import { WizardStepVendorTime } from "@/app/(protected)/workorders/_components/wizard/wizard-step-vendor-time";
+import { useNewWoWizardState } from "@/app/(protected)/workorders/_components/wizard/use-new-wo-wizard-state";
 
 type NewWoWizardProps = {
   open: boolean;
   onOpenChange: (open: boolean) => void;
   users: WorkOrderUser[];
+  existingRows?: WorkOrderTableRow[];
+  onViewExistingWo?: (row: WorkOrderTableRow) => void;
 };
 
 function WizardStepHeader({ step }: { step: number }) {
@@ -75,152 +60,99 @@ function WizardStepHeader({ step }: { step: number }) {
   );
 }
 
-export function NewWoWizard({ open, onOpenChange, users }: NewWoWizardProps) {
-  const mockFallback = isWoWizardMockEnabled();
-  const [step, setStep] = useState(1);
-  const [draft, setDraft] = useState<WorkOrderWizardDraft>({
-    ...EMPTY_WIZARD_DRAFT,
-    status: "Incomplete",
-  });
-  const [pocAutoFilledFor, setPocAutoFilledFor] = useState("");
-
-  const { data: apiLocations = [] } = useWorkOrderLocations();
-  const { data: apiProblems = [] } = useDropdownOptionsByCategory("Problem");
-  const isMockLocation = draft.locationId.startsWith("mock-");
-  const { data: apiLocationDetail } = useLocationDetail(
-    isMockLocation ? undefined : draft.locationId || undefined,
-  );
-  const mockLocationDetail = isMockLocation
-    ? getMockWoWizardLocationDetail(draft.locationId)
-    : undefined;
-  const locationDetail = mockLocationDetail ?? apiLocationDetail;
-  const { data: apiVendors = [] } = useWorkOrderVendors(
-    undefined,
-    isMockLocation ? undefined : locationDetail?.zipCode,
-  );
-  const createMutation = useCreateWorkOrderFromWizard(() => onOpenChange(false));
-
-  const wizardUsers = useMemo(() => {
-    if (users.length > 0) {
-      return users;
-    }
-    return mockFallback ? MOCK_WO_WIZARD_USERS : [];
-  }, [mockFallback, users]);
-  const locations =
-    apiLocations.length > 0 ? apiLocations : mockFallback ? MOCK_WO_WIZARD_LOCATIONS : [];
-  const problems =
-    apiProblems.length > 0 ? apiProblems : mockFallback ? MOCK_WO_WIZARD_SERVICES : [];
-  const vendors = apiVendors.length > 0 ? apiVendors : mockFallback ? MOCK_WO_WIZARD_VENDORS : [];
-
-  useEffect(() => {
-    if (open) {
-      setStep(1);
-      setDraft({ ...EMPTY_WIZARD_DRAFT, status: "Incomplete" });
-      setPocAutoFilledFor("");
-    }
-  }, [open]);
-
-  useEffect(() => {
-    if (!draft.locationId || !locationDetail) {
-      return;
-    }
-    if (pocAutoFilledFor === draft.locationId) {
-      return;
-    }
-    setDraft((current) => ({
-      ...current,
-      pocName: locationDetail.contact ?? current.pocName,
-      pocPhone: locationDetail.phone ?? current.pocPhone,
-    }));
-    setPocAutoFilledFor(draft.locationId);
-  }, [draft.locationId, locationDetail, pocAutoFilledFor]);
-
-  const setField = <K extends keyof WorkOrderWizardDraft>(
-    key: K,
-    value: WorkOrderWizardDraft[K],
-  ) => {
-    setDraft((current) => ({ ...current, [key]: value }));
-  };
-
-  const patchDraft = (patch: Partial<WorkOrderWizardDraft>) => {
-    setDraft((current) => ({ ...current, ...patch }));
-    if (patch.locationId !== undefined && patch.locationId !== pocAutoFilledFor) {
-      setPocAutoFilledFor("");
-    }
-  };
-
-  const handleCreate = () => createMutation.mutate(draft);
+export function NewWoWizard({
+  open,
+  onOpenChange,
+  users,
+  existingRows = [],
+  onViewExistingWo,
+}: NewWoWizardProps) {
+  const wizard = useNewWoWizardState({ open, users, existingRows, onOpenChange });
 
   return (
-    <Dialog
-      open={open}
-      onClose={() => onOpenChange(false)}
-      maxWidth={false}
-      slotProps={{
-        ...dialogBlurBackdropSlotProps,
-        paper: {
-          className: "flex flex-col overflow-hidden p-0",
-          style: {
-            borderRadius: 12,
-            width: 768,
-            maxWidth: 768,
-            height: 680,
-            maxHeight: 680,
+    <>
+      <Dialog
+        open={open}
+        onClose={() => onOpenChange(false)}
+        maxWidth={false}
+        slotProps={{
+          ...dialogBlurBackdropSlotProps,
+          paper: {
+            className: "flex flex-col overflow-hidden p-0",
+            style: {
+              borderRadius: 12,
+              width: 768,
+              maxWidth: 768,
+              height: 680,
+              maxHeight: 680,
+            },
           },
-        },
-      }}
-    >
-      <span className="sr-only">Guided setup for creating a new work order</span>
+        }}
+      >
+        <span className="sr-only">Guided setup for creating a new work order</span>
 
-      <div className="flex min-h-0 flex-1">
-        <WizardSidebar step={step} draft={draft} />
+        <div className="flex min-h-0 flex-1">
+          <WizardSidebar step={wizard.step} draft={wizard.draft} />
 
-        <div
-          className="min-h-0 flex-1 overflow-y-auto"
-          style={{ padding: 32, background: "var(--color-bg-surface)" }}
-        >
-          <WizardStepHeader step={step} />
+          <div
+            className="min-h-0 flex-1 overflow-y-auto"
+            style={{ padding: 32, background: "var(--color-bg-surface)" }}
+          >
+            <WizardStepHeader step={wizard.step} />
 
-          {step === 1 && (
-            <WizardStepTypeSchedule
-              draft={draft}
-              users={wizardUsers}
-              onUpdate={setField}
-              onPatch={patchDraft}
-            />
-          )}
+            {wizard.step === 1 && (
+              <WizardStepTypeSchedule
+                draft={wizard.draft}
+                users={wizard.wizardUsers}
+                onUpdate={wizard.setField}
+                onPatch={wizard.patchDraft}
+                onDuplicateWoNumber={wizard.handleDuplicateFound}
+              />
+            )}
 
-          {step === 2 && (
-            <WizardStepLocationService
-              draft={draft}
-              locations={locations}
-              locationDetail={locationDetail}
-              services={problems.map((p) => ({ id: p.id, value: p.value }))}
-              onUpdate={setField}
-              onPatch={patchDraft}
-            />
-          )}
+            {wizard.step === 2 && (
+              <WizardStepLocationService
+                draft={wizard.draft}
+                locations={wizard.locations}
+                locationDetail={wizard.locationDetail}
+                services={wizard.problems.map((p) => ({ id: p.id, value: p.value }))}
+                onUpdate={wizard.setField}
+                onPatch={wizard.patchDraft}
+              />
+            )}
 
-          {step === 3 && (
-            <WizardStepVendorTime
-              draft={draft}
-              vendors={vendors}
-              onUpdate={setField}
-              onPatch={patchDraft}
-            />
-          )}
+            {wizard.step === 3 && (
+              <WizardStepVendorTime
+                draft={wizard.draft}
+                vendors={wizard.vendors}
+                onUpdate={wizard.setField}
+                onPatch={wizard.patchDraft}
+              />
+            )}
+          </div>
         </div>
-      </div>
 
-      <WizardFooter
-        step={step}
-        draft={draft}
-        onCancel={() => onOpenChange(false)}
-        onBack={() => setStep((s) => s - 1)}
-        onContinue={() => setStep((s) => s + 1)}
-        onCreate={handleCreate}
-        isCreating={createMutation.isPending}
+        <WizardFooter
+          step={wizard.step}
+          draft={wizard.draft}
+          onCancel={() => onOpenChange(false)}
+          onBack={() => wizard.setStep((s) => s - 1)}
+          onContinue={() => wizard.setStep((s) => s + 1)}
+          onCreate={wizard.handleCreate}
+          isCreating={wizard.isCreating}
+        />
+      </Dialog>
+
+      <DuplicateWoNumberDialog
+        open={wizard.duplicateRow != null}
+        existing={wizard.duplicateRow}
+        onDismiss={() => wizard.setDuplicateRow(null)}
+        onViewExisting={(row) => {
+          wizard.setDuplicateRow(null);
+          onOpenChange(false);
+          onViewExistingWo?.(row);
+        }}
       />
-    </Dialog>
+    </>
   );
 }

src/app/(protected)/workorders/_components/wizard/use-new-wo-wizard-state.ts

@@ -0,0 +1,136 @@
+import { useEffect, useMemo, useState } from "react";
+import { isWoWizardMockEnabled } from "@/domain/work-orders/mocks/is-wo-wizard-mock-enabled";
+import {
+  getMockWoWizardLocationDetail,
+  MOCK_WO_WIZARD_LOCATIONS,
+  MOCK_WO_WIZARD_SERVICES,
+  MOCK_WO_WIZARD_USERS,
+  MOCK_WO_WIZARD_VENDORS,
+} from "@/domain/work-orders/mocks/wo-wizard-mock-data";
+import type { WorkOrderUser } from "@/domain/work-orders/types/work-order";
+import type { WorkOrderTableRow } from "@/domain/work-orders/types/work-order-table-row";
+import {
+  EMPTY_WIZARD_DRAFT,
+  type WorkOrderWizardDraft,
+} from "@/domain/work-orders/types/work-order-wizard";
+import { useLocationDetail } from "@/domain/locations/use-cases/use-location-detail";
+import { useDropdownOptionsByCategory } from "@/domain/settings/dropdown-options/use-cases/use-dropdown-options-by-category";
+import {
+  useWorkOrderLocations,
+  useWorkOrderVendors,
+} from "@/domain/work-orders/use-cases/use-work-order-detail";
+import { useCreateWorkOrderFromWizard } from "@/domain/work-orders/use-cases/use-create-work-order-from-wizard";
+import { useWizardDuplicateActions } from "./use-wizard-duplicate-actions";
+
+type UseNewWoWizardStateArgs = {
+  open: boolean;
+  users: WorkOrderUser[];
+  existingRows: WorkOrderTableRow[];
+  onOpenChange: (open: boolean) => void;
+};
+
+export function useNewWoWizardState({
+  open,
+  users,
+  existingRows,
+  onOpenChange,
+}: UseNewWoWizardStateArgs) {
+  const mockFallback = isWoWizardMockEnabled();
+  const [step, setStep] = useState(1);
+  const [draft, setDraft] = useState<WorkOrderWizardDraft>({
+    ...EMPTY_WIZARD_DRAFT,
+    status: "Incomplete",
+  });
+  const [pocAutoFilledFor, setPocAutoFilledFor] = useState("");
+
+  const { data: apiLocations = [] } = useWorkOrderLocations();
+  const { data: apiProblems = [] } = useDropdownOptionsByCategory("Problem");
+  const isMockLocation = draft.locationId.startsWith("mock-");
+  const { data: apiLocationDetail } = useLocationDetail(
+    isMockLocation ? undefined : draft.locationId || undefined,
+  );
+  const mockLocationDetail = isMockLocation
+    ? getMockWoWizardLocationDetail(draft.locationId)
+    : undefined;
+  const locationDetail = mockLocationDetail ?? apiLocationDetail;
+  const { data: apiVendors = [] } = useWorkOrderVendors(
+    undefined,
+    isMockLocation ? undefined : locationDetail?.zipCode,
+  );
+  const createMutation = useCreateWorkOrderFromWizard(() => onOpenChange(false));
+  const { duplicateRow, setDuplicateRow, handleDuplicateFound, handleCreate, isCreating } =
+    useWizardDuplicateActions({
+      open,
+      draft,
+      existingRows,
+      createMutation,
+    });
+
+  const wizardUsers = useMemo(() => {
+    if (users.length > 0) {
+      return users;
+    }
+    return mockFallback ? MOCK_WO_WIZARD_USERS : [];
+  }, [mockFallback, users]);
+  const locations =
+    apiLocations.length > 0 ? apiLocations : mockFallback ? MOCK_WO_WIZARD_LOCATIONS : [];
+  const problems =
+    apiProblems.length > 0 ? apiProblems : mockFallback ? MOCK_WO_WIZARD_SERVICES : [];
+  const vendors = apiVendors.length > 0 ? apiVendors : mockFallback ? MOCK_WO_WIZARD_VENDORS : [];
+
+  useEffect(() => {
+    if (open) {
+      setStep(1);
+      setDraft({ ...EMPTY_WIZARD_DRAFT, status: "Incomplete" });
+      setPocAutoFilledFor("");
+      setDuplicateRow(null);
+    }
+  }, [open, setDuplicateRow]);
+
+  useEffect(() => {
+    if (!draft.locationId || !locationDetail) {
+      return;
+    }
+    if (pocAutoFilledFor === draft.locationId) {
+      return;
+    }
+    setDraft((current) => ({
+      ...current,
+      pocName: locationDetail.contact ?? current.pocName,
+      pocPhone: locationDetail.phone ?? current.pocPhone,
+    }));
+    setPocAutoFilledFor(draft.locationId);
+  }, [draft.locationId, locationDetail, pocAutoFilledFor]);
+
+  const setField = <K extends keyof WorkOrderWizardDraft>(
+    key: K,
+    value: WorkOrderWizardDraft[K],
+  ) => {
+    setDraft((current) => ({ ...current, [key]: value }));
+  };
+
+  const patchDraft = (patch: Partial<WorkOrderWizardDraft>) => {
+    setDraft((current) => ({ ...current, ...patch }));
+    if (patch.locationId !== undefined && patch.locationId !== pocAutoFilledFor) {
+      setPocAutoFilledFor("");
+    }
+  };
+
+  return {
+    step,
+    setStep,
+    draft,
+    duplicateRow,
+    setDuplicateRow,
+    wizardUsers,
+    locations,
+    problems,
+    vendors,
+    locationDetail,
+    setField,
+    patchDraft,
+    handleDuplicateFound,
+    handleCreate,
+    isCreating,
+  };
+}

src/app/(protected)/workorders/_components/wizard/use-wizard-duplicate-actions.ts

@@ -0,0 +1,100 @@
+import { useEffect, useRef, useState } from "react";
+import { toast } from "react-toastify";
+import type { WorkOrderTableRow } from "@/domain/work-orders/types/work-order-table-row";
+import type { WorkOrderWizardDraft } from "@/domain/work-orders/types/work-order-wizard";
+import { findDuplicateWoNumberRow } from "@/domain/work-orders/utils/find-duplicate-wo-number-row";
+import { workOrdersApi } from "@/domain/work-orders/api/work-orders-api";
+
+type UseWizardDuplicateActionsArgs = {
+  open: boolean;
+  draft: WorkOrderWizardDraft;
+  existingRows: WorkOrderTableRow[];
+  createMutation: {
+    mutate: (draft: WorkOrderWizardDraft) => void;
+    isPending: boolean;
+  };
+};
+
+export function useWizardDuplicateActions({
+  open,
+  draft,
+  existingRows,
+  createMutation,
+}: UseWizardDuplicateActionsArgs) {
+  const [duplicateRow, setDuplicateRow] = useState<WorkOrderTableRow | null>(null);
+  const [isCheckingDuplicate, setIsCheckingDuplicate] = useState(false);
+  const openRef = useRef(open);
+  const draftRef = useRef(draft);
+
+  useEffect(() => {
+    openRef.current = open;
+  }, [open]);
+
+  useEffect(() => {
+    draftRef.current = draft;
+  }, [draft]);
+
+  const resolveDuplicate = async (woNumber: string) => {
+    const localDuplicate = findDuplicateWoNumberRow(woNumber, existingRows);
+    if (localDuplicate) {
+      return localDuplicate;
+    }
+
+    // The loaded board rows are only an immediate UX hint; the unfiltered API lookup is authoritative.
+    return workOrdersApi.findByWoNumber(woNumber);
+  };
+
+  const handleDuplicateFound = (woNumber: string) => {
+    void (async () => {
+      try {
+        const duplicate = await resolveDuplicate(woNumber);
+        // Ignore stale lookups after dismiss or after the user edits the WO#.
+        if (!openRef.current || woNumber !== draftRef.current.woNumber) {
+          return;
+        }
+        if (duplicate) {
+          setDuplicateRow(duplicate);
+        }
+      } catch {
+        if (!openRef.current) {
+          return;
+        }
+        toast.error("Unable to verify the work order number. Please try again.");
+      }
+    })();
+  };
+
+  const handleCreate = () => {
+    const woNumberAtSubmit = draft.woNumber;
+    void (async () => {
+      setIsCheckingDuplicate(true);
+      try {
+        const duplicate = await resolveDuplicate(woNumberAtSubmit);
+        // Ignore after dismiss or if the WO# changed while the request was in flight.
+        if (!openRef.current || woNumberAtSubmit !== draftRef.current.woNumber) {
+          return;
+        }
+        if (duplicate) {
+          setDuplicateRow(duplicate);
+          return;
+        }
+        createMutation.mutate(draftRef.current);
+      } catch {
+        if (!openRef.current) {
+          return;
+        }
+        toast.error("Unable to verify the work order number. Please try again.");
+      } finally {
+        setIsCheckingDuplicate(false);
+      }
+    })();
+  };
+
+  return {
+    duplicateRow,
+    setDuplicateRow,
+    handleDuplicateFound,
+    handleCreate,
+    isCreating: createMutation.isPending || isCheckingDuplicate,
+  };
+}

src/app/(protected)/workorders/_components/wizard/wizard-step-type-schedule.tsx

@@ -116,6 +116,7 @@ type WizardStepTypeScheduleProps = {
   users: WorkOrderUser[];
   onUpdate: <K extends keyof WorkOrderWizardDraft>(key: K, value: WorkOrderWizardDraft[K]) => void;
   onPatch: (patch: Partial<WorkOrderWizardDraft>) => void;
+  onDuplicateWoNumber?: (woNumber: string) => void;
 };
 
 export function WizardStepTypeSchedule({
@@ -123,6 +124,7 @@ export function WizardStepTypeSchedule({
   users,
   onUpdate,
   onPatch,
+  onDuplicateWoNumber,
 }: WizardStepTypeScheduleProps) {
   return (
     <div className="space-y-6">
@@ -137,6 +139,7 @@ export function WizardStepTypeSchedule({
           type="text"
           value={draft.woNumber}
           onChange={(e) => onUpdate("woNumber", e.target.value)}
+          onBlur={() => onDuplicateWoNumber?.(draft.woNumber)}
           placeholder="e.g. 24818"
           maxLength={20}
           className={DLG_INPUT_CLS}

src/app/(protected)/workorders/index.tsx

@@ -9,8 +9,8 @@ import { WorkOrdersAdvancedFiltersBanner } from "@/app/(protected)/workorders/_c
 import { WorkOrdersFilterBar } from "@/app/(protected)/workorders/_components/list/filter-bar/work-orders-filter-bar";
 import { WorkOrdersListHeader } from "@/app/(protected)/workorders/_components/list/work-orders-list-header";
 import { WorkOrderCancelDialog } from "@/app/(protected)/workorders/_components/list/work-order-cancel-dialog";
+import { WorkOrdersListWizard } from "@/app/(protected)/workorders/_components/list/work-orders-list-wizard";
 import { WoTable } from "@/app/(protected)/workorders/_components/list/table/wo-table";
-import { NewWoWizard } from "@/app/(protected)/workorders/_components/wizard/new-wo-wizard";
 import { useWorkOrdersListPage } from "@/app/(protected)/workorders/_hooks/use-work-orders-list-page";
 import { useAuthContext } from "@/providers/auth-context";
 
@@ -91,7 +91,13 @@ export default function WorkOrdersListPage() {
         onPatch={page.patchField}
       />
 
-      <NewWoWizard open={page.wizardOpen} onOpenChange={page.setWizardOpen} users={page.users} />
+      <WorkOrdersListWizard
+        open={page.wizardOpen}
+        onOpenChange={page.setWizardOpen}
+        users={page.users}
+        rows={tableData.rows}
+        onViewExisting={(row) => page.handleOpenSlideOver(row, false)}
+      />
 
       <WorkOrdersAdvancedSearchSheet
         open={filters.advOpen}

src/domain/work-orders/api/work-orders-api.ts

@@ -191,6 +191,48 @@ export const workOrdersApi = {
     };
   },
 
+  findByWoNumber: async (woNumber: string): Promise<WorkOrderTableRow | undefined> => {
+    const normalized = woNumber.trim();
+    // Search every non-empty WO# — backend advanced search accepts 1-character queries, and
+    // wizard/create allow single-digit numbers (SH-189 must not bypass remote uniqueness).
+    if (!normalized) {
+      return undefined;
+    }
+    // Safety cap — if hit before exhausting results, fail closed (do not treat as unique).
+    const safetyMaxPages = 50;
+
+    // `board/search` is fuzzy and paginated (0-based); exhaust pages for an exact WO#.
+    const pageSize = 100;
+    let page = 0;
+    let scanned = 0;
+    let totalCount = Number.POSITIVE_INFINITY;
+
+    while (scanned < totalCount) {
+      if (page >= safetyMaxPages) {
+        throw new Error(
+          "Unable to verify the work order number: search result set exceeded the safety page limit.",
+        );
+      }
+      const result = await workOrdersApi.searchBoard({
+        search: normalized,
+        page,
+        pageSize,
+      });
+      const exact = result.items.find((row) => row.woNumber === normalized);
+      if (exact) {
+        return exact;
+      }
+      scanned += result.items.length;
+      totalCount = result.totalCount;
+      if (result.items.length === 0) {
+        break;
+      }
+      page += 1;
+    }
+
+    return undefined;
+  },
+
   getListByLocation: async (
     locationId: string | number,
     search = "",

src/domain/work-orders/utils/find-duplicate-wo-number-row.ts

@@ -0,0 +1,16 @@
+import type { WorkOrderTableRow } from "@/domain/work-orders/types/work-order-table-row";
+
+export function findDuplicateWoNumberRow(
+  woNumber: string,
+  rows: WorkOrderTableRow[],
+  excludeId?: string | number,
+): WorkOrderTableRow | undefined {
+  const normalized = woNumber.trim();
+  if (normalized === "") {
+    return undefined;
+  }
+
+  return rows.find(
+    (row) => row.woNumber === normalized && String(row.id) !== String(excludeId ?? ""),
+  );
+}

src/test/app/(protected)/workorders/duplicate-wo-number-dialog.test.tsx

@@ -0,0 +1,58 @@
+import { fireEvent, screen } from "@testing-library/react";
+import { describe, expect, it, vi } from "vitest";
+import { DuplicateWoNumberDialog } from "@/app/(protected)/workorders/_components/list/duplicate-wo-number-dialog";
+import type { WorkOrderTableRow } from "@/domain/work-orders/types/work-order-table-row";
+import { renderWithProviders } from "@/test/test-utils";
+
+const existingRow = { id: "wo-99", woNumber: "12345678901" } as WorkOrderTableRow;
+
+describe("DuplicateWoNumberDialog", () => {
+  it("shows the duplicate title and work order number when open", () => {
+    renderWithProviders(
+      <DuplicateWoNumberDialog
+        open
+        existing={existingRow}
+        onDismiss={vi.fn()}
+        onViewExisting={vi.fn()}
+      />,
+    );
+
+    expect(screen.getByRole("dialog")).toBeInTheDocument();
+    expect(screen.getByText("Duplicate Work Order Number")).toBeInTheDocument();
+    expect(screen.getByText(/12345678901/)).toBeInTheDocument();
+  });
+
+  it("calls onViewExisting when View existing is clicked", () => {
+    const onViewExisting = vi.fn();
+
+    renderWithProviders(
+      <DuplicateWoNumberDialog
+        open
+        existing={existingRow}
+        onDismiss={vi.fn()}
+        onViewExisting={onViewExisting}
+      />,
+    );
+
+    fireEvent.click(screen.getByRole("button", { name: "View existing" }));
+
+    expect(onViewExisting).toHaveBeenCalledWith(existingRow);
+  });
+
+  it("calls onDismiss when Dismiss is clicked", () => {
+    const onDismiss = vi.fn();
+
+    renderWithProviders(
+      <DuplicateWoNumberDialog
+        open
+        existing={existingRow}
+        onDismiss={onDismiss}
+        onViewExisting={vi.fn()}
+      />,
+    );
+
+    fireEvent.click(screen.getByRole("button", { name: "Dismiss" }));
+
+    expect(onDismiss).toHaveBeenCalledTimes(1);
+  });
+});

src/test/app/(protected)/workorders/new-wo-wizard-duplicate.test.tsx

@@ -0,0 +1,88 @@
+import { fireEvent, screen, waitFor } from "@testing-library/react";
+import { describe, expect, it, vi } from "vitest";
+import { NewWoWizard } from "@/app/(protected)/workorders/_components/wizard/new-wo-wizard";
+import type { WorkOrderTableRow } from "@/domain/work-orders/types/work-order-table-row";
+import { renderWithProviders } from "@/test/test-utils";
+
+const existingRow = { id: "wo-99", woNumber: "12345678901" } as WorkOrderTableRow;
+const findByWoNumber = vi.fn();
+
+vi.mock("@/domain/work-orders/use-cases/use-create-work-order-from-wizard", () => ({
+  useCreateWorkOrderFromWizard: () => ({
+    mutate: vi.fn(),
+    isPending: false,
+  }),
+}));
+
+vi.mock("@/domain/work-orders/use-cases/use-work-order-detail", () => ({
+  useWorkOrderLocations: () => ({ data: [] }),
+  useWorkOrderVendors: () => ({ data: [] }),
+}));
+
+vi.mock("@/domain/locations/use-cases/use-location-detail", () => ({
+  useLocationDetail: () => ({ data: undefined }),
+}));
+
+vi.mock("@/domain/settings/dropdown-options/use-cases/use-dropdown-options-by-category", () => ({
+  useDropdownOptionsByCategory: () => ({ data: [] }),
+}));
+
+vi.mock("@/domain/work-orders/api/work-orders-api", () => ({
+  workOrdersApi: {
+    findByWoNumber: (...args: unknown[]) => findByWoNumber(...args),
+  },
+}));
+
+describe("NewWoWizard duplicate wo number", () => {
+  it("shows the duplicate dialog when the wizard wo number matches an existing row", async () => {
+    renderWithProviders(
+      <NewWoWizard
+        open
+        onOpenChange={vi.fn()}
+        users={[]}
+        existingRows={[existingRow]}
+        onViewExistingWo={vi.fn()}
+      />,
+    );
+
+    const woNumberInput = screen.getByPlaceholderText("e.g. 24818");
+    fireEvent.change(woNumberInput, {
+      target: { value: "12345678901" },
+    });
+    fireEvent.blur(woNumberInput);
+
+    await waitFor(() => {
+      expect(screen.getByText("Duplicate Work Order Number")).toBeInTheDocument();
+    });
+    expect(screen.getByText(/is already assigned to another work order/i)).toBeInTheDocument();
+  });
+
+  it("finds a duplicate outside the loaded board rows", async () => {
+    const offPageRow = {
+      id: "wo-off-page",
+      woNumber: "98765432109",
+    } as WorkOrderTableRow;
+    findByWoNumber.mockResolvedValueOnce(offPageRow);
+
+    renderWithProviders(
+      <NewWoWizard
+        open
+        onOpenChange={vi.fn()}
+        users={[]}
+        existingRows={[]}
+        onViewExistingWo={vi.fn()}
+      />,
+    );
+
+    const woNumberInput = screen.getByPlaceholderText("e.g. 24818");
+    fireEvent.change(woNumberInput, {
+      target: { value: "98765432109" },
+    });
+    fireEvent.blur(woNumberInput);
+
+    await waitFor(() => {
+      expect(screen.getByText("Duplicate Work Order Number")).toBeInTheDocument();
+    });
+    expect(findByWoNumber).toHaveBeenCalledWith("98765432109");
+  });
+});

src/test/app/(protected)/workorders/use-wo-table-row-handlers-duplicate.test.ts

@@ -0,0 +1,43 @@
+import { renderHook } from "@testing-library/react";
+import { describe, expect, it, vi } from "vitest";
+import { useWoTableRowHandlers } from "@/app/(protected)/workorders/_components/list/table/use-wo-table-row-handlers";
+import type { WorkOrderTableRow } from "@/domain/work-orders/types/work-order-table-row";
+
+const existingRow = { id: "wo-99", woNumber: "12345678901" } as WorkOrderTableRow;
+
+function buildTableData() {
+  return {
+    dragState: { current: { dragId: null, overId: null } },
+    setDragViz: vi.fn(),
+    reorderRows: vi.fn(),
+    endDrag: vi.fn(),
+    setUnschedOpen: vi.fn(),
+    triggerFlash: vi.fn(),
+    setSelectedId: vi.fn(),
+  } as never;
+}
+
+describe("useWoTableRowHandlers onDuplicateFound", () => {
+  it("delegates to onDuplicateFound instead of opening the slide-over", () => {
+    const onDuplicateFound = vi.fn();
+    const onOpenSlideOver = vi.fn();
+
+    const { result } = renderHook(() =>
+      useWoTableRowHandlers({
+        tableData: buildTableData(),
+        weekMonday: "2026-07-20",
+        onWeekChange: vi.fn(),
+        onOpenSlideOver,
+        onOpenMedia: vi.fn(),
+        onPatch: vi.fn(),
+        onScheduleHighlight: vi.fn(),
+        onDuplicateFound,
+      }),
+    );
+
+    result.current.onDuplicateFound?.(existingRow);
+
+    expect(onDuplicateFound).toHaveBeenCalledWith(existingRow);
+    expect(onOpenSlideOver).not.toHaveBeenCalled();
+  });
+});

src/test/domain/work-orders/api/work-orders-api.test.ts

@@ -299,6 +299,157 @@ describe("workOrdersApi.searchBoard", () => {
   });
 });
 
+describe("workOrdersApi.findByWoNumber", () => {
+  beforeEach(() => {
+    apiGet.mockReset();
+  });
+
+  it("searches globally without the active board filters", async () => {
+    apiGet.mockResolvedValue({
+      items: [
+        {
+          id: 505,
+          woNumber: "10000001235",
+          lifecycleStatusLabel: "Incomplete",
+        },
+      ],
+      totalCount: 1,
+      page: 0,
+      pageSize: 100,
+    });
+
+    const result = await workOrdersApi.findByWoNumber("10000001235");
+
+    expect(apiGet).toHaveBeenCalledWith(
+      API_PATHS.workOrder.boardSearch,
+      expect.objectContaining({
+        searchParams: expect.any(URLSearchParams),
+      }),
+    );
+    const searchParams = apiGet.mock.calls[0]?.[1]?.searchParams as URLSearchParams;
+    expect(Object.fromEntries(searchParams)).toEqual({
+      search: "10000001235",
+      page: "0",
+      pageSize: "100",
+    });
+    expect(result).toMatchObject({ id: 505, woNumber: "10000001235" });
+  });
+
+  it("pages through fuzzy search until the exact WO number is found", async () => {
+    apiGet
+      .mockResolvedValueOnce({
+        items: Array.from({ length: 100 }, (_, index) => ({
+          id: index + 1,
+          woNumber: `fuzzy-match-${index}`,
+          lifecycleStatusLabel: "Incomplete",
+        })),
+        totalCount: 101,
+        page: 0,
+        pageSize: 100,
+      })
+      .mockResolvedValueOnce({
+        items: [
+          {
+            id: 999,
+            woNumber: "10000009999",
+            lifecycleStatusLabel: "Incomplete",
+          },
+        ],
+        totalCount: 101,
+        page: 1,
+        pageSize: 100,
+      });
+
+    const result = await workOrdersApi.findByWoNumber("10000009999");
+
+    expect(apiGet).toHaveBeenCalledTimes(2);
+    const secondParams = apiGet.mock.calls[1]?.[1]?.searchParams as URLSearchParams;
+    expect(Object.fromEntries(secondParams)).toMatchObject({
+      search: "10000009999",
+      page: "1",
+      pageSize: "100",
+    });
+    expect(result).toMatchObject({ id: 999, woNumber: "10000009999" });
+  });
+
+  it("skips remote search for empty WO numbers", async () => {
+    const result = await workOrdersApi.findByWoNumber("   ");
+    expect(apiGet).not.toHaveBeenCalled();
+    expect(result).toBeUndefined();
+  });
+
+  it("finds a one-character WO number duplicate outside loaded board rows", async () => {
+    apiGet.mockResolvedValue({
+      items: [
+        {
+          id: 7,
+          woNumber: "9",
+          lifecycleStatusLabel: "Incomplete",
+        },
+      ],
+      totalCount: 1,
+      page: 0,
+      pageSize: 100,
+    });
+
+    const result = await workOrdersApi.findByWoNumber("9");
+
+    expect(apiGet).toHaveBeenCalledTimes(1);
+    const searchParams = apiGet.mock.calls[0]?.[1]?.searchParams as URLSearchParams;
+    expect(Object.fromEntries(searchParams)).toEqual({
+      search: "9",
+      page: "0",
+      pageSize: "100",
+    });
+    expect(result).toMatchObject({ id: 7, woNumber: "9" });
+  });
+
+  it("throws when the safety page limit is hit before exhausting results", async () => {
+    apiGet.mockResolvedValue({
+      items: Array.from({ length: 100 }, (_, index) => ({
+        id: index + 1,
+        woNumber: `fuzzy-match-${index}`,
+        lifecycleStatusLabel: "Incomplete",
+      })),
+      totalCount: 10_000,
+      page: 0,
+      pageSize: 100,
+    });
+
+    await expect(workOrdersApi.findByWoNumber("10000005555")).rejects.toThrow(/safety page limit/i);
+    expect(apiGet).toHaveBeenCalledTimes(50);
+  });
+
+  it("returns undefined after exhausting all fuzzy search pages", async () => {
+    apiGet
+      .mockResolvedValueOnce({
+        items: Array.from({ length: 100 }, (_, index) => ({
+          id: index + 1,
+          woNumber: `fuzzy-match-${index}`,
+          lifecycleStatusLabel: "Incomplete",
+        })),
+        totalCount: 150,
+        page: 0,
+        pageSize: 100,
+      })
+      .mockResolvedValueOnce({
+        items: Array.from({ length: 50 }, (_, index) => ({
+          id: index + 101,
+          woNumber: `fuzzy-match-${index + 100}`,
+          lifecycleStatusLabel: "Incomplete",
+        })),
+        totalCount: 150,
+        page: 1,
+        pageSize: 100,
+      });
+
+    const result = await workOrdersApi.findByWoNumber("10000005555");
+
+    expect(apiGet).toHaveBeenCalledTimes(2);
+    expect(result).toBeUndefined();
+  });
+});
+
 describe("workOrdersApi.patchBoardField", () => {
   beforeEach(() => {
     apiPatchFn.mockReset();

src/test/domain/work-orders/utils/find-duplicate-wo-number-row.test.ts

@@ -0,0 +1,19 @@
+import { describe, expect, it } from "vitest";
+import { findDuplicateWoNumberRow } from "@/domain/work-orders/utils/find-duplicate-wo-number-row";
+import type { WorkOrderTableRow } from "@/domain/work-orders/types/work-order-table-row";
+
+const rows = [
+  { id: "wo-1", woNumber: "12345678901" },
+  { id: "wo-2", woNumber: "99999999999" },
+] as WorkOrderTableRow[];
+
+describe("findDuplicateWoNumberRow", () => {
+  it("returns a matching row when the wo number already exists", () => {
+    expect(findDuplicateWoNumberRow("12345678901", rows)).toEqual(rows[0]);
+  });
+
+  it("ignores blank values and excluded ids", () => {
+    expect(findDuplicateWoNumberRow("", rows)).toBeUndefined();
+    expect(findDuplicateWoNumberRow("12345678901", rows, "wo-1")).toBeUndefined();
+  });
+});

tmp/pr-descriptions/pr8-duplicate-dialog.md

@@ -0,0 +1,26 @@
+## Jira
+
+- [SH-189](https://luby-us.atlassian.net/browse/SH-189)
+
+## QA residual
+
+- P0 done: duplicate dialog also on **wizard create** (not only table cell).
+- P1 polish: Cancel / View Existing copy tweaks.
+
+## Summary
+
+- Show a confirmation dialog when inline WO number editing **or wizard create** detects a duplicate instead of navigating immediately to the existing work order.
+- Dialog title: **Duplicate Work Order Number**; actions: **View existing** (opens the existing WO via slide-over route) and **Dismiss** (closes the dialog and keeps the current row editable).
+- Duplicate scan logic shared via `find-duplicate-wo-number-row`.
+
+## Test plan
+
+- [ ] Edit a WO number in the table to match an existing row → dialog opens with the duplicate number in the message.
+- [ ] Click **Dismiss** → dialog closes; edited row keeps its original number.
+- [ ] Repeat duplicate entry → click **View existing** → navigates to `/workorders/{id}` for the existing row.
+- [ ] Wizard create with duplicate WO number → same dialog; **View existing** closes wizard and opens `/workorders/{id}`.
+
+## Out of scope
+
+- Server-side uniqueness (422) handling
+- SH provisional numbering