diff --git a/src/domain/work-orders/mappers/work-order-board-patch-mapper.ts b/src/domain/work-orders/mappers/work-order-board-patch-mapper.ts
index c3e55a58..87d68f25 100644
--- a/src/domain/work-orders/mappers/work-order-board-patch-mapper.ts
+++ b/src/domain/work-orders/mappers/work-order-board-patch-mapper.ts
@@ -42,6 +42,7 @@ const LOCAL_ONLY_KEYS = new Set<keyof WorkOrderTablePatch>([
   "originalDate",
   /** Optimistic overlay only — backend owns isAddOn after schedule ops (SH-184). */
   "isAddOn",
+  "primaryDispatchStatus",
 ]);
 
 export function isLocalOnlyTablePatch(patch: WorkOrderTablePatch): boolean {
diff --git a/src/test/domain/work-orders/mappers/work-order-board-patch-mapper.test.ts b/src/test/domain/work-orders/mappers/work-order-board-patch-mapper.test.ts
index f26d13fe..8e728756 100644
--- a/src/test/domain/work-orders/mappers/work-order-board-patch-mapper.test.ts
+++ b/src/test/domain/work-orders/mappers/work-order-board-patch-mapper.test.ts
@@ -5,6 +5,7 @@ import {
   isLocalOnlyTablePatch,
   mapDocStatusToApi,
 } from "@/domain/work-orders/mappers/work-order-board-patch-mapper";
+import { toVendorTablePatch } from "@/domain/work-orders/utils/vendor-assignment-patch";
 
 describe("mapDocStatusToApi", () => {
   it("maps NN to NotNeeded", () => {
@@ -25,6 +26,10 @@ describe("isLocalOnlyTablePatch", () => {
   it("does not treat site as local-only", () => {
     expect(isLocalOnlyTablePatch({ site: "BK5" })).toBe(false);
   });
+
+  it("treats primaryDispatchStatus overlay as local-only", () => {
+    expect(isLocalOnlyTablePatch({ primaryDispatchStatus: "" })).toBe(true);
+  });
 });
 
 describe("expandTablePatchToBoardFieldOps", () => {
@@ -136,6 +141,17 @@ describe("expandTablePatchToBoardFieldOps", () => {
       }),
     ).toEqual([{ field: "vendorId", value: "7" }]);
 
+    expect(
+      expandTablePatchToBoardFieldOps(
+        toVendorTablePatch({
+          vendorId: "9",
+          company: "New Co",
+          tech: "Pat",
+          techPhone: "555",
+        }),
+      ),
+    ).toEqual([{ field: "vendorId", value: "9" }]);
+
     expect(
       expandTablePatchToBoardFieldOps({
         site: "BK5",
diff --git a/src/test/domain/work-orders/utils/wo-closability.test.ts b/src/test/domain/work-orders/utils/wo-closability.test.ts
index 240ed796..9d97358d 100644
--- a/src/test/domain/work-orders/utils/wo-closability.test.ts
+++ b/src/test/domain/work-orders/utils/wo-closability.test.ts
@@ -449,6 +449,30 @@ describe("tableRowToClosabilityInput", () => {
     });
     expect(getClosabilityGaps(input)).toEqual([]);
   });
+
+  it.each(["Pending", "Sent"] as const)(
+    "keeps company assignment after vendor save when primary dispatch status is %s",
+    (primaryDispatchStatus) => {
+      const input = tableRowToClosabilityInput({
+        ...closableRow,
+        company: "New Co",
+        vendorId: "9",
+        primaryDispatchStatus,
+      });
+      expect(input.vendorId).toBe("9");
+      expect(getClosabilityGaps(input)).not.toContain("Company");
+    },
+  );
+
+  it("raises Company when leftover Refused remains on the patched vendor id", () => {
+    const input = tableRowToClosabilityInput({
+      ...closableRow,
+      company: "New Co",
+      vendorId: "9",
+      primaryDispatchStatus: "Refused",
+    });
+    expect(getClosabilityGaps(input)).toContain("Company");
+  });
 });
 
 describe("readDetailWoType", () => {