diff --git a/background.js b/background.js
index 48b997e..df04191 100644
--- a/background.js
+++ b/background.js
@@ -10898,6 +10898,7 @@ const phoneVerificationHelpers = self.MultiPageBackgroundPhoneVerification?.crea
   DEFAULT_PHONE_CODE_TIMEOUT_WINDOWS,
   DEFAULT_PHONE_CODE_POLL_INTERVAL_SECONDS,
   DEFAULT_PHONE_CODE_POLL_ROUNDS,
+  readAuthTabSnapshot,
   ensureStep8SignupPageReady,
   navigateAuthTabToAddPhone: async (tabId, options = {}) => {
     const visibleStep = Math.floor(Number(options.visibleStep || options.step) || 0) || 9;
@@ -12204,6 +12205,26 @@ async function ensureStep8SignupPageReady(tabId, options = {}) {
   });
 }
 
+async function readAuthTabSnapshot(tabId) {
+  if (!Number.isInteger(tabId)) {
+    return null;
+  }
+  try {
+    const executionResults = await chrome.scripting.executeScript({
+      target: { tabId },
+      world: 'ISOLATED',
+      func: () => ({
+        url: String(location.href || ''),
+        title: String(document.title || ''),
+        text: String(document.body?.innerText || document.documentElement?.innerText || '').trim(),
+      }),
+    });
+    return executionResults?.[0]?.result || null;
+  } catch {
+    return null;
+  }
+}
+
 async function getStep8PageState(tabId, responseTimeoutMs = 1500, visibleStep = 9) {
   try {
     const result = await sendTabMessageWithTimeout(tabId, 'signup-page', {
diff --git a/background/phone-verification-flow.js b/background/phone-verification-flow.js
index 193adff..7cd9694 100644
--- a/background/phone-verification-flow.js
+++ b/background/phone-verification-flow.js
@@ -11,6 +11,7 @@
       getOAuthFlowStepTimeoutMs,
       getState,
       requestStop = null,
+      readAuthTabSnapshot = null,
       sendToContentScript,
       sendToContentScriptResilient,
       navigateAuthTabToAddPhone = null,
@@ -1407,6 +1408,44 @@
       return new Error(`${PHONE_RESEND_SERVER_ERROR_PREFIX}${message || 'OpenAI contact-verification page returned HTTP ERROR 500 after resend.'}`);
     }
 
+    function getPhoneResendServerErrorFromSnapshot(snapshot = {}) {
+      const rawUrl = String(snapshot?.url || snapshot?.href || '').trim();
+      if (!/\/contact-verification(?:[/?#]|$)/i.test(rawUrl)) {
+        return '';
+      }
+      const combined = [
+        snapshot?.text,
+        snapshot?.bodyText,
+        snapshot?.title,
+      ]
+        .filter(Boolean)
+        .join(' ')
+        .replace(/\s+/g, ' ')
+        .trim();
+      if (!isPhoneResendServerError(combined)) {
+        return '';
+      }
+      return combined || 'OpenAI contact-verification page returned HTTP ERROR 500 after resend.';
+    }
+
+    async function readPhoneResendServerErrorFromAuthTab(tabId) {
+      if (typeof readAuthTabSnapshot !== 'function') {
+        return '';
+      }
+      try {
+        return getPhoneResendServerErrorFromSnapshot(await readAuthTabSnapshot(tabId));
+      } catch (_) {
+        return '';
+      }
+    }
+
+    async function throwPhoneResendServerErrorIfAuthTabShowsIt(tabId) {
+      const serverErrorText = await readPhoneResendServerErrorFromAuthTab(tabId);
+      if (serverErrorText) {
+        throw buildPhoneResendServerError(serverErrorText);
+      }
+    }
+
     function shouldTreatResendThrottledAsBanned(state = {}) {
       return Boolean(state?.phoneResendThrottledAsBannedEnabled);
     }
@@ -5457,6 +5496,7 @@
                   if (isPhoneResendServerError(resendError)) {
                     throw buildPhoneResendServerError(resendError);
                   }
+                  await throwPhoneResendServerErrorIfAuthTabShowsIt(tabId);
                   await addLog(`步骤 4：注册手机验证码页面重发失败，将继续轮询短信。${resendError.message}`, 'warn', {
                     step: 4,
                     stepKey: 'fetch-signup-code',
@@ -5497,6 +5537,7 @@
                 if (isPhoneResendServerError(resendError)) {
                   throw buildPhoneResendServerError(resendError);
                 }
+                await throwPhoneResendServerErrorIfAuthTabShowsIt(tabId);
                 await addLog(`步骤 4：验证码被拒后点击重发失败。${resendError.message}`, 'warn', {
                   step: 4,
                   stepKey: 'fetch-signup-code',
diff --git a/tests/phone-verification-flow.test.js b/tests/phone-verification-flow.test.js
index 3533d17..705ae17 100644
--- a/tests/phone-verification-flow.test.js
+++ b/tests/phone-verification-flow.test.js
@@ -5888,6 +5888,77 @@ test('signup phone verification cancels activation when resend lands on contact-
   assert.equal(currentState.signupPhoneActivation, null);
 });
 
+test('signup phone verification cancels activation when resend lands on contact-verification 500 page but content script drops', async () => {
+  const requests = [];
+  const tabSnapshots = [];
+  let currentState = {
+    heroSmsApiKey: 'demo-key',
+    heroSmsCountryId: 52,
+    heroSmsCountryLabel: 'Thailand',
+    verificationResendCount: 0,
+    phoneCodeWaitSeconds: 60,
+    phoneCodeTimeoutWindows: 2,
+    phoneCodePollIntervalSeconds: 1,
+    phoneCodePollMaxRounds: 1,
+    signupPhoneActivation: {
+      activationId: '930001',
+      phoneNumber: '66953330002',
+      provider: 'hero-sms',
+      countryId: 52,
+      countryLabel: 'Thailand',
+    },
+  };
+
+  const helpers = api.createPhoneVerificationHelpers({
+    addLog: async () => {},
+    fetchImpl: async (url) => {
+      const parsedUrl = new URL(url);
+      requests.push(parsedUrl);
+      const action = parsedUrl.searchParams.get('action');
+      const id = parsedUrl.searchParams.get('id');
+      if (action === 'getStatus') {
+        return { ok: true, text: async () => 'STATUS_WAIT_CODE' };
+      }
+      if (action === 'setStatus') {
+        return { ok: true, text: async () => `STATUS_UPDATED:${id}` };
+      }
+      throw new Error(`Unexpected HeroSMS action: ${action}`);
+    },
+    getState: async () => ({ ...currentState }),
+    readAuthTabSnapshot: async () => {
+      tabSnapshots.push('read');
+      return {
+        url: 'https://auth.openai.com/contact-verification',
+        title: 'auth.openai.com',
+        text: "This page isn't working auth.openai.com is currently unable to handle this request. HTTP ERROR 500",
+      };
+    },
+    sendToContentScriptResilient: async (_source, message) => {
+      if (message.type === 'RESEND_VERIFICATION_CODE') {
+        throw new Error('Could not establish connection. Receiving end does not exist.');
+      }
+      throw new Error(`Unexpected content-script message: ${message.type}`);
+    },
+    setState: async (updates) => {
+      currentState = { ...currentState, ...updates };
+    },
+    sleepWithStop: async () => {},
+    throwIfStopped: () => {},
+  });
+
+  await assert.rejects(
+    () => helpers.completeSignupPhoneVerificationFlow(1, { state: currentState }),
+    (error) => {
+      assert.match(error.message, /^PHONE_RESEND_SERVER_ERROR::This page isn't working/);
+      return true;
+    }
+  );
+
+  assert.equal(tabSnapshots.length >= 1, true);
+  assert.equal(currentState.signupPhoneActivation, null);
+  assert.equal(requests.filter((request) => request.searchParams.get('action') === 'getStatus').length, 1);
+});
+
 test('phone verification helper skips page resend for 5sim timeouts and rotates number directly', async () => {
   const requests = [];
   const messages = [];