diff --git a/src/components/orders-review-modal.test.tsx b/src/components/orders-review-modal.test.tsx
index 9db64ca..b6d2e35 100644
--- a/src/components/orders-review-modal.test.tsx
+++ b/src/components/orders-review-modal.test.tsx
@@ -5,19 +5,30 @@ vi.mock("@/components/ui/customer-search", () => ({
   CustomerSearch: ({
     onValueChange,
     value,
+    customers,
   }: {
     onValueChange: (v: string) => void;
     value: string;
     customers: unknown[];
-  }) => (
-    <button
-      type="button"
-      data-testid="customer-search-mock"
-      onClick={() => onValueChange("cust-new")}
-    >
-      {value || "(unset)"}
-    </button>
-  ),
+  }) => {
+    // Surface the first non-selected customer's id as a data attribute
+    // so cascade tests can click it specifically. Falls back to
+    // "cust-new" when there's no other customer in the list.
+    const others = (customers as Array<{ id: string }>).filter(
+      (c) => c.id !== value,
+    );
+    const nextId = others[0]?.id ?? "cust-new";
+    return (
+      <button
+        type="button"
+        data-testid="customer-search-mock"
+        data-next-id={nextId}
+        onClick={() => onValueChange(nextId)}
+      >
+        {value || "(unset)"}
+      </button>
+    );
+  },
 }));
 
 vi.mock("sonner", () => ({
@@ -688,4 +699,73 @@ describe("OrdersReviewModal", () => {
       expect(rekeyedRow?.getAttribute("data-pending-removal")).toBe("false");
     });
   });
+
+  describe("customer cascade (company + rep)", () => {
+    const expandedCustomerA: Customer = {
+      ...baseCustomer,
+      id: "cust-A",
+      customer: "Alice Anderson",
+      company: "comp-A",
+      expand: {
+        company: { ...baseCompany, id: "comp-A", company: "Atlas Corp" },
+        rep: { id: "user-1", name: "Riya Patel", email: "riya@atlas.test" },
+      },
+    };
+    const expandedCustomerB: Customer = {
+      ...baseCustomer,
+      id: "cust-B",
+      customer: "Bob Brown",
+      company: "comp-B",
+      expand: {
+        company: { ...baseCompany, id: "comp-B", company: "Beacon Ltd" },
+        rep: { id: "user-2", name: "Sam Jones", email: "sam@beacon.test" },
+      },
+    };
+
+    it("updates Company and Rep labels when the customer changes", () => {
+      const props = {
+        ...baseProps(),
+        customers: [expandedCustomerA, expandedCustomerB],
+        customer: expandedCustomerA,
+        order: { ...baseOrder, customer: "cust-A", company: "comp-A", rep: "Riya Patel" },
+      };
+      render(<OrdersReviewModal {...props} />);
+
+      // Baseline: Company and Rep show the persisted (A) values.
+      expect(screen.getByText("Atlas Corp")).toBeInTheDocument();
+      expect(screen.getByText("Riya Patel")).toBeInTheDocument();
+      expect(screen.queryByText("Beacon Ltd")).not.toBeInTheDocument();
+
+      // Pick customer B. The mock's data-next-id is computed from the
+      // customer list, so the click will pass cust-B.
+      fireEvent.click(screen.getByTestId("customer-search-mock"));
+
+      // Company and Rep should now reflect customer B's expands.
+      expect(screen.getByText("Beacon Ltd")).toBeInTheDocument();
+      expect(screen.getByText("Sam Jones")).toBeInTheDocument();
+      // The original A values are no longer in the labels.
+      expect(screen.queryByText("Atlas Corp")).not.toBeInTheDocument();
+      expect(screen.queryByText("Riya Patel")).not.toBeInTheDocument();
+    });
+
+    it("marks the modal dirty after a customer change cascades", () => {
+      const props = {
+        ...baseProps(),
+        customers: [expandedCustomerA, expandedCustomerB],
+        customer: expandedCustomerA,
+        order: { ...baseOrder, customer: "cust-A", company: "comp-A", rep: "Riya Patel" },
+      };
+      render(<OrdersReviewModal {...props} />);
+
+      // Find the Save button by accessible name. The modal's primary
+      // save action is the only one in the footer.
+      const saveBefore = screen.getByRole("button", { name: /save/i });
+      expect(saveBefore).toBeDisabled();
+
+      fireEvent.click(screen.getByTestId("customer-search-mock"));
+
+      const saveAfter = screen.getByRole("button", { name: /save/i });
+      expect(saveAfter).not.toBeDisabled();
+    });
+  });
 });