diff --git a/background/steps/fill-plus-checkout.js b/background/steps/fill-plus-checkout.js
index 89133ec..78168f2 100644
--- a/background/steps/fill-plus-checkout.js
+++ b/background/steps/fill-plus-checkout.js
@@ -423,8 +423,7 @@
       }
       await addLog(`步骤 7：GPC 模式开始 OTP 验证（reference_id: ${referenceId}）...`, 'info');
       let otp = '';
-      const useLocalSmsHelper = Boolean(state?.gopayHelperLocalSmsHelperEnabled)
-        && normalizeGpcOtpChannel(state?.gopayHelperOtpChannel) === 'sms';
+      const useLocalSmsHelper = Boolean(state?.gopayHelperLocalSmsHelperEnabled);
       if (useLocalSmsHelper) {
         try {
           await addLog('步骤 7：正在从本地 SMS Helper 等待 GPC OTP...', 'info');
diff --git a/sidepanel/sidepanel.js b/sidepanel/sidepanel.js
index 62525a5..dbbc2b9 100644
--- a/sidepanel/sidepanel.js
+++ b/sidepanel/sidepanel.js
@@ -3147,7 +3147,7 @@ function collectSettingsPayload() {
       ? selectGpcHelperOtpChannel.value
       : (latestState?.gopayHelperOtpChannel || 'whatsapp')
   );
-  const selectedGpcLocalSmsHelperEnabled = selectedGpcOtpChannel === 'sms' && Boolean(
+  const selectedGpcLocalSmsHelperEnabled = Boolean(
     typeof inputGpcHelperLocalSmsEnabled !== 'undefined' && inputGpcHelperLocalSmsEnabled
       ? inputGpcHelperLocalSmsEnabled.checked
       : latestState?.gopayHelperLocalSmsHelperEnabled
@@ -7014,8 +7014,8 @@ function updatePlusModeUI() {
     ? normalizePlusPaymentMethod(selectPlusPaymentMethod.value)
     : method;
   const gpcRowsVisible = enabled && selectedMethod === gpcValue;
-  const localSmsControlsVisible = gpcRowsVisible && gpcOtpChannel === 'sms';
-  const effectiveLocalSmsEnabled = gpcOtpChannel === 'sms' && localSmsEnabled;
+  const localSmsControlsVisible = gpcRowsVisible;
+  const effectiveLocalSmsEnabled = localSmsEnabled;
   if (typeof selectPlusPaymentMethod !== 'undefined' && selectPlusPaymentMethod) {
     selectPlusPaymentMethod.value = method;
     if (selectPlusPaymentMethod.style) {
@@ -11229,9 +11229,6 @@ selectPlusPaymentMethod?.addEventListener('change', () => {
     scheduleSettingsAutoSave();
   });
   input?.addEventListener('change', () => {
-    if (input === inputGpcHelperLocalSmsEnabled && input.checked && selectGpcHelperOtpChannel) {
-      selectGpcHelperOtpChannel.value = 'sms';
-    }
     if (input === selectGpcHelperOtpChannel || input === inputGpcHelperLocalSmsEnabled) {
       updatePlusModeUI();
     }
diff --git a/tests/plus-checkout-billing-tab-resolution.test.js b/tests/plus-checkout-billing-tab-resolution.test.js
index 43005ea..4fabdec 100644
--- a/tests/plus-checkout-billing-tab-resolution.test.js
+++ b/tests/plus-checkout-billing-tab-resolution.test.js
@@ -932,6 +932,65 @@ test('GPC billing reads OTP from local SMS helper when enabled', async () => {
   assert.equal(events.completed[0].step, 7);
 });
 
+test('GPC billing can read WhatsApp OTP from local helper when enabled', async () => {
+  const fetchCalls = [];
+  const { events, executor } = createExecutorHarness({
+    frames: [],
+    stateByFrame: {},
+    fetchImpl: async (url, options = {}) => {
+      fetchCalls.push({ url, options });
+      if (url.startsWith('http://127.0.0.1:18767/otp')) {
+        return {
+          ok: true,
+          status: 200,
+          json: async () => ({ ok: true, otp: '765432', message_id: 'wa-1' }),
+        };
+      }
+      if (url.endsWith('/api/gopay/otp')) {
+        return {
+          ok: true,
+          status: 200,
+          json: async () => ({ reference_id: 'ref_wa', challenge_id: 'challenge_wa' }),
+        };
+      }
+      if (url.endsWith('/api/gopay/pin')) {
+        return {
+          ok: true,
+          status: 200,
+          json: async () => ({ stage: 'gopay_complete' }),
+        };
+      }
+      throw new Error(`unexpected url: ${url}`);
+    },
+  });
+
+  await executor.executePlusCheckoutBilling({
+    plusPaymentMethod: 'gpc-helper',
+    plusCheckoutSource: 'gpc-helper',
+    gopayHelperReferenceId: 'ref_wa',
+    gopayHelperApiUrl: 'https://gopay.hwork.pro/',
+    gopayHelperPin: '654321',
+    gopayHelperCardKey: 'card_wa',
+    gopayHelperOtpChannel: 'whatsapp',
+    gopayHelperLocalSmsHelperEnabled: true,
+    gopayHelperLocalSmsHelperUrl: 'http://127.0.0.1:18767',
+    gopayHelperPhoneNumber: '+8613800138000',
+  });
+
+  assert.equal(events.states.some((state) => state.plusManualConfirmationMethod === 'gopay-otp'), false);
+  assert.equal(events.states.some((state) => state.gopayHelperResolvedOtp === '765432'), true);
+  const helperUrl = new URL(fetchCalls[0].url);
+  assert.equal(helperUrl.origin + helperUrl.pathname, 'http://127.0.0.1:18767/otp');
+  assert.equal(helperUrl.searchParams.get('reference_id'), 'ref_wa');
+  assert.equal(helperUrl.searchParams.get('phone_number'), '+8613800138000');
+  assert.deepEqual(JSON.parse(fetchCalls[1].options.body), {
+    reference_id: 'ref_wa',
+    otp: '765432',
+    card_key: 'card_wa',
+  });
+  assert.equal(events.completed[0].step, 7);
+});
+
 test('GPC billing retries OTP with compatibility field after HTTP 400', async () => {
   const fetchCalls = [];
   let currentState = {
diff --git a/tests/sidepanel-plus-payment-method.test.js b/tests/sidepanel-plus-payment-method.test.js
index b05f552..dc0f5fa 100644
--- a/tests/sidepanel-plus-payment-method.test.js
+++ b/tests/sidepanel-plus-payment-method.test.js
@@ -257,24 +257,20 @@ return {
   assert.equal(api.rows.rowGpcHelperCardKey.style.display, '');
   assert.equal(api.rows.rowGpcHelperPhone.style.display, '');
   assert.equal(api.rows.rowGpcHelperOtpChannel.style.display, '');
-  assert.equal(api.rows.rowGpcHelperLocalSmsEnabled.style.display, 'none');
+  assert.equal(api.rows.rowGpcHelperLocalSmsEnabled.style.display, '');
   assert.equal(api.rows.rowGpcHelperLocalSmsUrl.style.display, 'none');
   assert.match(api.plusPaymentMethodCaption.textContent, /GPC/);
 
-  api.selectGpcHelperOtpChannel.value = 'sms';
-  api.updatePlusModeUI();
-  assert.equal(api.rows.rowGpcHelperLocalSmsEnabled.style.display, '');
-  assert.equal(api.rows.rowGpcHelperLocalSmsUrl.style.display, 'none');
-
   api.inputGpcHelperLocalSmsEnabled.checked = true;
   api.updatePlusModeUI();
+  assert.equal(api.selectGpcHelperOtpChannel.value, 'whatsapp');
   assert.equal(api.rows.rowGpcHelperLocalSmsUrl.style.display, '');
 
-  api.selectGpcHelperOtpChannel.value = 'whatsapp';
+  api.selectGpcHelperOtpChannel.value = 'sms';
   api.updatePlusModeUI();
-  assert.equal(api.inputGpcHelperLocalSmsEnabled.checked, false);
-  assert.equal(api.rows.rowGpcHelperLocalSmsEnabled.style.display, 'none');
-  assert.equal(api.rows.rowGpcHelperLocalSmsUrl.style.display, 'none');
+  assert.equal(api.inputGpcHelperLocalSmsEnabled.checked, true);
+  assert.equal(api.rows.rowGpcHelperLocalSmsEnabled.style.display, '');
+  assert.equal(api.rows.rowGpcHelperLocalSmsUrl.style.display, '');
 
   api.selectPlusPaymentMethod.value = 'gopay';
   api.updatePlusModeUI();