diff --git a/src/browser-client.ts b/src/browser-client.ts
index 7018b6d..aa4df7c 100644
--- a/src/browser-client.ts
+++ b/src/browser-client.ts
@@ -372,6 +372,14 @@ class BrowserClientImpl implements BrowserClient, UserStateHost, UserCallHost {
       if (this.#loopController.signal.aborted) break;
       if (end.failure !== undefined) this.#emitFailure(end.failure);
       if (this.#loopController.signal.aborted) break;
+      if (end.failure instanceof BrowserClientError
+        && end.failure.kind === 'authorization'
+        && !end.failure.retryable) {
+        // Asking again cannot change the answer: stop instead of looping.
+        this.#startDeferred?.reject(end.failure);
+        void this.stop();
+        break;
+      }
       this.#transition('reconnecting', undefined, end.failure);
       if (this.#loopController.signal.aborted) break;
       if (endedSession !== undefined
@@ -436,7 +444,11 @@ class BrowserClientImpl implements BrowserClient, UserStateHost, UserCallHost {
         return this.#options.credentialProvider.getCredential(request);
       })
       .then((value) => validateBrowserRelayCredential(value, this.#runtime.now()))
-      .catch(() => { throw browserUnavailable('Browser relay credential provider failed'); });
+      .catch((error: unknown) => {
+        // A permanent refusal (home deleted, access withdrawn) stays permanent.
+        if (error instanceof BrowserClientError && !error.retryable) throw error;
+        throw browserUnavailable('Browser relay credential provider failed');
+      });
     const timeout = this.#runtime.setTimer(() => {
       child.controller.abort(browserUnavailable('Browser relay credential request timed out'));
     }, Math.max(1, Math.min(timeoutMs, SESSION_PHASE_TIMEOUT_MS)));
diff --git a/src/browser-relay-credential-provider.ts b/src/browser-relay-credential-provider.ts
index 2d3490a..aae9543 100644
--- a/src/browser-relay-credential-provider.ts
+++ b/src/browser-relay-credential-provider.ts
@@ -13,6 +13,14 @@ import {
   parseResponseJson,
   type JsonValue,
 } from './internal/control-plane-response.js';
+import { BrowserClientError } from './internal/browser-errors.js';
+
+/**
+ * Statuses the control plane uses for answers that will not change by asking
+ * again: a home that does not exist (404), an account that may not open it
+ * (403), a request it cannot accept (400). Retrying them only burns quota.
+ */
+const PERMANENT_REFUSALS = new Set([400, 403, 404]);
 
 const HOME_ID = /^[a-z][a-z0-9-]{1,61}[a-z0-9]$/;
 const BASE64URL = /^[A-Za-z0-9_-]+$/;
@@ -201,6 +209,15 @@ async function exchangeCredential(
       signal: request.signal,
     } as RequestInit), request.signal);
     if (request.signal.aborted) throw abortReason(request.signal);
+    if (PERMANENT_REFUSALS.has(response.status)) {
+      cancelResponseBody(response);
+      throw new BrowserClientError(
+        'authorization',
+        'not_dispatched',
+        `The control plane refused to open this home (HTTP ${response.status})`,
+        { code: response.status, retryable: false },
+      );
+    }
     if (response.status !== 200 || response.redirected || response.type === 'opaqueredirect') {
       cancelResponseBody(response);
       return exchangeFailure();
@@ -215,11 +232,12 @@ async function exchangeCredential(
     const body = await withAbort(boundedResponseBody(response, request.signal), request.signal);
     if (request.signal.aborted) throw abortReason(request.signal);
     return credentialResponse(parseResponseJson(body), firebaseIdToken, appCheckToken, Date.now());
-  } catch {
+  } catch (error) {
     if (request.signal.aborted) {
       cancelResponseBody(response);
       throw abortReason(request.signal);
     }
+    if (error instanceof BrowserClientError && !error.retryable) throw error;
     return exchangeFailure();
   }
 }
diff --git a/test/browser-relay-credential-provider.test.ts b/test/browser-relay-credential-provider.test.ts
index ef305bd..e995c72 100644
--- a/test/browser-relay-credential-provider.test.ts
+++ b/test/browser-relay-credential-provider.test.ts
@@ -284,6 +284,19 @@ describe('control-plane browser relay credential provider', () => {
     }
   });
 
+  test('reports a refusal that asking again cannot change as permanent', async () => {
+    for (const status of [400, 403, 404]) {
+      const provider = createControlPlaneBrowserRelayCredentialProvider(options(
+        async () => new Response('{"error":{"code":"home_not_found","retryable":false}}', {
+          status,
+          headers: successHeaders(),
+        }),
+      ));
+      const failure = await provider.getCredential(request()).catch((error: unknown) => error);
+      expect(failure).toMatchObject({ kind: 'authorization', retryable: false, code: status });
+    }
+  });
+
   test('coalesces only identical in-flight requests', async () => {
     let release: (() => void) | undefined;
     const gate = new Promise<void>((resolve) => { release = resolve; });