diff --git a/apps/web/src/lib/api/client.test.ts b/apps/web/src/lib/api/client.test.ts
index 02bfb602..552acb81 100644
--- a/apps/web/src/lib/api/client.test.ts
+++ b/apps/web/src/lib/api/client.test.ts
@@ -149,46 +149,73 @@ describe("fetchWithAuth refresh handling", () => {
 });
 
 describe("payment-required redirect", () => {
-  test("bills the workspace the request was sent for", async () => {
-    // Switching workspaces can change the active workspace while a request is
-    // in flight. Its 402 belongs to the workspace in its X-Company-ID header.
-    const replaced: string[] = [];
-    const originalWindow = (globalThis as { window?: unknown }).window;
-    const originalBillingUrl = process.env.VITE_BILLING_URL;
+  const originalWindow = (globalThis as { window?: unknown }).window;
+  const originalBillingUrl = process.env.VITE_BILLING_URL;
+  let replaced: string[] = [];
+  let respond: (response: Response) => void = () => undefined;
+  let sentCompanyId = null as string | null;
+
+  function stubBrowser(pathname: string): void {
+    replaced = [];
     (globalThis as { window?: unknown }).window = {
       location: {
         origin: "https://app.example.com",
+        pathname,
         replace: (url: string) => replaced.push(url),
       },
     };
     process.env.VITE_BILLING_URL = "/billing";
-
-    let respond: (response: Response) => void = () => undefined;
-    let sentCompanyId = null as string | null;
     globalThis.fetch = ((_input: RequestInfo | URL, init?: RequestInit) => {
       sentCompanyId = (init?.headers as Record<string, string>)["X-Company-ID"];
       return new Promise<Response>((resolve) => {
         respond = resolve;
       });
     }) as unknown as typeof fetch;
+  }
+
+  async function answerWith402(request: Promise<unknown>): Promise<void> {
+    respond(
+      Response.json({ error: "SUBSCRIPTION_RESTRICTED" }, { status: 402 }),
+    );
+    await expect(request).rejects.toThrow();
+  }
+
+  afterEach(() => {
+    (globalThis as { window?: unknown }).window = originalWindow;
+    if (originalBillingUrl === undefined) delete process.env.VITE_BILLING_URL;
+    else process.env.VITE_BILLING_URL = originalBillingUrl;
+  });
+
+  test("bills the workspace the request was sent for", async () => {
+    stubBrowser("/w/new-workspace/chat");
+    setCompanyId("new-workspace");
+    await answerWith402(fetchWithAuth("/companies"));
+
+    expect(sentCompanyId).toBe("new-workspace");
+    expect(replaced).toEqual([
+      "/billing?companyId=new-workspace&mode=onboarding",
+    ]);
+  });
+
+  test("ignores a 402 for a workspace the user has left", async () => {
+    // Switching away from a workspace that needs payment must not be undone by
+    // a request that was still in flight for it.
+    stubBrowser("/w/paid-workspace/chat");
+    setCompanyId("unpaid-workspace");
+    const request = fetchWithAuth("/notifications/count");
+    setCompanyId("paid-workspace");
+    await answerWith402(request);
+
+    expect(sentCompanyId).toBe("unpaid-workspace");
+    expect(replaced).toEqual([]);
+  });
+
+  test("never redirects away from the workspace chooser", async () => {
+    // The chooser is how a user leaves a workspace that needs payment.
+    stubBrowser("/workspaces");
+    setCompanyId("unpaid-workspace");
+    await answerWith402(fetchWithAuth("/notifications/count"));
 
-    try {
-      setCompanyId("new-workspace");
-      const request = fetchWithAuth("/companies");
-      setCompanyId("previous-workspace");
-      respond(
-        Response.json({ error: "SUBSCRIPTION_RESTRICTED" }, { status: 402 }),
-      );
-
-      await expect(request).rejects.toThrow();
-      expect(sentCompanyId).toBe("new-workspace");
-      expect(replaced).toEqual([
-        "/billing?companyId=new-workspace&mode=onboarding",
-      ]);
-    } finally {
-      (globalThis as { window?: unknown }).window = originalWindow;
-      if (originalBillingUrl === undefined) delete process.env.VITE_BILLING_URL;
-      else process.env.VITE_BILLING_URL = originalBillingUrl;
-    }
+    expect(replaced).toEqual([]);
   });
 });
diff --git a/apps/web/src/lib/api/client.ts b/apps/web/src/lib/api/client.ts
index 74bc7540..12c642a5 100644
--- a/apps/web/src/lib/api/client.ts
+++ b/apps/web/src/lib/api/client.ts
@@ -4,6 +4,7 @@
  */
 
 import { getWorkspaceBillingUrl } from "../billing-url.js";
+import { isWorkspaceChooserPath } from "../workspace-routes.js";
 import type { RefreshResponse } from "./types.js";
 
 // API Configuration
@@ -30,6 +31,14 @@ function redirectToBillingOnPaymentRequired(
   ) {
     return;
   }
+  // A 402 for a workspace the user has since left is stale: following it
+  // would pull them back into the workspace they just switched away from.
+  // This relies on WorkspaceRouteGuard not reverting a switch in flight;
+  // otherwise a new workspace's 402 could arrive after a revert and be dropped.
+  if (workspaceId !== companyId) return;
+  // The chooser is the way out of a workspace that needs payment, so it must
+  // never redirect back into that workspace's billing page.
+  if (isWorkspaceChooserPath(window.location.pathname)) return;
 
   const billingUrl = getWorkspaceBillingUrl(workspaceId, { onboarding: true });
   if (!billingUrl) return;
diff --git a/apps/web/src/lib/workspace-routes.test.ts b/apps/web/src/lib/workspace-routes.test.ts
index da213fef..d0d1127b 100644
--- a/apps/web/src/lib/workspace-routes.test.ts
+++ b/apps/web/src/lib/workspace-routes.test.ts
@@ -3,6 +3,7 @@ import type { MemberPermissions } from "@wateaminbox/shared";
 import {
   chatViewPath,
   getWorkspaceDestination,
+  isWorkspaceChooserPath,
   parseChatView,
   resolveInitialWorkspaceId,
   resolveWorkspaceDestination,
@@ -139,3 +140,12 @@ describe("chat view query param", () => {
     });
   });
 });
+
+describe("isWorkspaceChooserPath", () => {
+  test("matches the chooser with or without a trailing slash", () => {
+    expect(isWorkspaceChooserPath("/workspaces")).toBe(true);
+    expect(isWorkspaceChooserPath("/workspaces/")).toBe(true);
+    expect(isWorkspaceChooserPath("/w/abc/chat")).toBe(false);
+    expect(isWorkspaceChooserPath("/workspaces-old")).toBe(false);
+  });
+});
diff --git a/apps/web/src/lib/workspace-routes.ts b/apps/web/src/lib/workspace-routes.ts
index 1b8fb6ea..bd47a56c 100644
--- a/apps/web/src/lib/workspace-routes.ts
+++ b/apps/web/src/lib/workspace-routes.ts
@@ -1,5 +1,12 @@
 import type { MemberPermissions } from "@wateaminbox/shared";
 
+/** Account-level page for choosing a workspace; it belongs to no workspace. */
+export const WORKSPACE_CHOOSER_PATH = "/workspaces";
+
+export function isWorkspaceChooserPath(pathname: string): boolean {
+  return pathname.replace(/\/+$/, "") === WORKSPACE_CHOOSER_PATH;
+}
+
 export function resolveInitialWorkspaceId(
   availableWorkspaceIds: string[],
   routeWorkspaceId: string | null,