diff --git a/src/domain/work-orders/errors/board-patch-errors.ts b/src/domain/work-orders/errors/board-patch-errors.ts
index 00779894..2335502b 100644
--- a/src/domain/work-orders/errors/board-patch-errors.ts
+++ b/src/domain/work-orders/errors/board-patch-errors.ts
@@ -24,10 +24,20 @@ export class BoardPatchValidationError extends Error {
 
 export const DISPATCH_REQUIRED_MESSAGE = "Select a vendor company before saving.";
 
-/** why: backend field names must never be exposed through user-facing board toasts. */
+export const BOARD_PATCH_FAILED_MESSAGE = "Unable to save the work order. Please try again.";
+
+export const NO_PERSISTABLE_FIELDS_MESSAGE =
+  "These changes cannot be saved on the board. Refresh and edit a supported field.";
+
+const KNOWN_VALIDATION_COPY: ReadonlyMap<string, string> = new Map([
+  ["DispatchRequired", DISPATCH_REQUIRED_MESSAGE],
+  ["NoPersistableFields", NO_PERSISTABLE_FIELDS_MESSAGE],
+]);
+
+/**
+ * why: board PATCH validation text ("vendorId is required…", object ids, backend codes)
+ * must never reach the screen. Unknown codes fall back to generic copy, not `error.message`.
+ */
 export function boardPatchValidationMessage(error: BoardPatchValidationError): string {
-  if (error.code === "DispatchRequired") {
-    return DISPATCH_REQUIRED_MESSAGE;
-  }
-  return error.message;
+  return KNOWN_VALIDATION_COPY.get(error.code) ?? BOARD_PATCH_FAILED_MESSAGE;
 }
diff --git a/src/domain/work-orders/use-cases/use-work-order-table-mutations.ts b/src/domain/work-orders/use-cases/use-work-order-table-mutations.ts
index a02950d3..0b17b328 100644
--- a/src/domain/work-orders/use-cases/use-work-order-table-mutations.ts
+++ b/src/domain/work-orders/use-cases/use-work-order-table-mutations.ts
@@ -6,6 +6,7 @@ import {
   boardPatchValidationMessage,
   BoardPatchConflictError,
   BoardPatchValidationError,
+  NO_PERSISTABLE_FIELDS_MESSAGE,
 } from "@/domain/work-orders/errors/board-patch-errors";
 import { mapApiStatusToWizard } from "@/domain/work-orders/mappers/wizard-draft-mapper";
 import {
@@ -58,10 +59,7 @@ async function applyBoardFieldOps(
 ): Promise<WorkOrderTableRow> {
   const ops = expandTablePatchToBoardFieldOps(patch);
   if (ops.length === 0) {
-    throw new BoardPatchValidationError(
-      "NoPersistableFields",
-      "These changes cannot be saved on the board. Refresh and edit a supported field.",
-    );
+    throw new BoardPatchValidationError("NoPersistableFields", NO_PERSISTABLE_FIELDS_MESSAGE);
   }
 
   const current = getRow?.(id);
diff --git a/src/test/domain/work-orders/use-cases/use-work-order-table-mutations-errors.test.tsx b/src/test/domain/work-orders/use-cases/use-work-order-table-mutations-errors.test.tsx
new file mode 100644
index 00000000..b9664f4b
--- /dev/null
+++ b/src/test/domain/work-orders/use-cases/use-work-order-table-mutations-errors.test.tsx
@@ -0,0 +1,86 @@
+import { QueryClientProvider } from "@tanstack/react-query";
+import { act, renderHook, waitFor } from "@testing-library/react";
+import type { ReactNode } from "react";
+import { toast } from "react-toastify";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import {
+  BOARD_PATCH_FAILED_MESSAGE,
+  DISPATCH_REQUIRED_MESSAGE,
+} from "@/domain/work-orders/errors/board-patch-errors";
+import type { WorkOrderTableRow } from "@/domain/work-orders/types/work-order-table-row";
+import { useWorkOrderTableMutations } from "@/domain/work-orders/use-cases/use-work-order-table-mutations";
+import { createTestQueryClient } from "@/test/test-utils";
+
+vi.mock("react-toastify", () => ({
+  toast: { error: vi.fn(), success: vi.fn(), warning: vi.fn() },
+}));
+
+const ROW = { id: 7, rowVersion: "v1" } as WorkOrderTableRow;
+
+function wrapper({ children }: { children: ReactNode }) {
+  return <QueryClientProvider client={createTestQueryClient()}>{children}</QueryClientProvider>;
+}
+
+/** Board PATCH goes through the real ky client; only the network response is faked. */
+function respondWith(status: number, body: Record<string, unknown>) {
+  globalThis.fetch = vi.fn(
+    async () =>
+      new Response(JSON.stringify(body), {
+        status,
+        headers: { "Content-Type": "application/json" },
+      }),
+  ) as typeof fetch;
+}
+
+async function patchAndGetToast(): Promise<unknown> {
+  const { result } = renderHook(
+    () =>
+      useWorkOrderTableMutations({
+        onPatch: () => undefined,
+        clearPatch: () => undefined,
+        getRow: () => ROW,
+      }),
+    { wrapper },
+  );
+  act(() => {
+    result.current.patchField(7, { woNumber: "WO-100" });
+  });
+  await waitFor(() => expect(toast.error).toHaveBeenCalledTimes(1));
+  expect(globalThis.fetch).toHaveBeenCalledTimes(1);
+  return vi.mocked(toast.error).mock.calls[0]?.[0];
+}
+
+describe("useWorkOrderTableMutations edit error copy", () => {
+  const originalFetch = globalThis.fetch;
+
+  beforeEach(() => {
+    vi.mocked(toast.error).mockClear();
+  });
+
+  afterEach(() => {
+    globalThis.fetch = originalFetch;
+  });
+
+  it("shows generic copy instead of backend text for an unknown 422 code", async () => {
+    respondWith(422, {
+      code: "InvalidLifecycleStatus",
+      message: "lifecycleStatus cannot move from Completed for workOrderId 7.",
+    });
+
+    const message = await patchAndGetToast();
+
+    expect(message).toBe(BOARD_PATCH_FAILED_MESSAGE);
+    expect(message).not.toMatch(/lifecycleStatus|workOrderId|InvalidLifecycleStatus/);
+  });
+
+  it("keeps specific copy for DispatchRequired", async () => {
+    respondWith(422, {
+      code: "DispatchRequired",
+      message: "vendorId is required when setting appointment fields.",
+    });
+
+    const message = await patchAndGetToast();
+
+    expect(message).toBe(DISPATCH_REQUIRED_MESSAGE);
+  });
+});