Guides / MFA SMS code not arriving (text message verification)

Part of: Sign-in, password and MFA problems

Last reviewed 6 Oct 2026 · By Harry

MFA SMS code not arriving (text message verification)

Verification text never arrives for Microsoft, Okta or Google sign-in? Phone, carrier, number and throttling checks, plus safer methods than SMS.

The sign-in page says We sent a code to your phone. Nothing comes. The user taps Resend four times, gets locked out, and calls the helpdesk. SMS is the least reliable multi-factor method because it depends on a mobile carrier, a phone number that may have changed, and message routing that nobody in your organisation controls. Here is how to get the user in today and reduce the next ticket.

Is the identity provider down?

Check the status page for whoever sends the code: Microsoft Entra ID for Microsoft 365, Okta, or Google Workspace. A real incident affects many users and usually more than SMS. If status is quiet and other people are receiving codes, the problem is local to this user.

User checks

1. Read the last digits on screen. The sign-in page usually shows the end of the registered number. If it is an old number, the code is going to someone else's phone or nowhere. Skip to the admin section.
2. Signal and mode. Turn airplane mode on and off. SMS needs cellular signal; Wi-Fi calling helps on some carriers and not others. Step outside or near a window.
3. Wait before resending. Repeated requests trigger throttling at the identity provider or the carrier, and the codes that do arrive may be out of order. Wait two or three minutes and use the most recent code only.
4. Blocked or filtered senders. Codes come from short codes or alphanumeric sender IDs. Check the phone's blocked numbers, spam/unknown sender filters, and any call-blocking apps. iPhone: Messages → Unknown Senders. Android: Messages → Spam and blocked.
5. Storage full. Some phones silently refuse new messages when storage is full. Delete a few large threads.
6. Roaming and abroad. Short-code SMS is sometimes not delivered when roaming. Try a voice call option if offered.
7. Try another method. If the sign-in page offers Sign in another way, choose the authenticator app, a voice call or a hardware key instead.

Admin fixes to get the user in

• Check the registered methods. In Entra admin centre, open the user → Authentication methods. In Okta, check the user's enrolled factors. Correct an outdated number, or require re-registration.
• Temporary Access Pass (Entra) or a one-time bypass (Okta). Issue a time-limited pass after verifying identity by a trusted route — a video call, a manager confirmation, or your documented process. Never issue one because a caller sounds urgent; MFA reset requests are a favourite social-engineering trick.
• Sign-in logs. The sign-in log shows whether MFA was requested, which method, and the failure reason. "User did not pass the MFA challenge" with no SMS sent points to throttling or a bad number.
• Carrier-wide issues. If several users on the same mobile network fail at once, the carrier is the likely cause. Check the carrier's own service status and move those users to app-based methods.
• Number recycled. If the number was reassigned, remove it immediately — a stranger now receives that user's codes.

Fix it properly: move off SMS

Microsoft, Okta and Google all recommend app-based or phishing-resistant methods over SMS. Push with number matching (see number matching not showing), passkeys and FIDO2 security keys survive carrier problems and SIM-swap fraud. Use authentication methods policy to set the app as the default and keep SMS as a fallback only. Make sure every user has at least two methods registered, and keep a documented recovery process so a lost phone is not a lost day — see lost phone recovery.

When to escalate

Escalate to the identity provider when their status page shows an MFA or telephony incident, or when users on different carriers all stop receiving codes at the same time. Escalate to the carrier when only their customers fail. One user with an old number on file needs an admin to update it, not a vendor ticket.

Related status pages

• Microsoft Entra ID
• Okta
• Google Workspace / Gmail

Related guides

• Microsoft Authenticator not getting notifications: fixes
• Okta Verify push not arriving or stuck in an MFA loop
• Lost phone or new phone: Microsoft Authenticator recovery

FAQ

Why is my MFA text code not arriving?

Common causes are an outdated phone number on your account, poor signal, carrier filtering of short codes, throttling after repeated resends, or a blocked sender. Try another sign-in method if offered.

How long should I wait before resending a code?

Wait two or three minutes. Repeated requests can trigger throttling and codes may arrive out of order. Always use the most recent code.

Can IT let me in without the code?

Admins can update your phone number or issue a temporary pass, such as an Entra Temporary Access Pass, after verifying your identity through the organisation’s approved process.

Is SMS a safe MFA method?

It is better than no MFA but is the weakest common method. Authenticator apps with number matching, passkeys and security keys are more reliable and resist SIM-swap fraud.