A Microsoft app for iOS and Android devices that enables authentication with two-factor verification, phone sign-in, and code generation
This usually happens because the approval notification is still being sent to the old phone where Microsoft Authenticator was last used.
Try this in order:
- On the sign-in page, select Other ways to sign in or Sign in another way.
- If available, choose another verification method such as SMS, phone, email, security key, or another backup method.
- If the old phone is still available at all, open Microsoft Authenticator on that device and approve the sign-in there.
- After access is restored, remove the old phone from the account’s security info and add the new phone as the sign-in method.
- If the app on the new phone still does not work, make sure:
- Microsoft Authenticator is unlocked
- app notifications are enabled
- the app is updated to the latest version
- the phone has internet access; switching between Wi‑Fi and mobile data can help
- the phone’s date and time are correct
Because this is a school account, if no other sign-in method is available and the old phone cannot be used, the practical fix is to contact the school IT administrator or help desk and ask them to reset MFA or allow re-registration of Microsoft Authenticator on the new phone. After they reset it, sign in again and set up Authenticator on the new device.
If verification codes are also not arriving, avoid making repeated requests, check whether texts from unknown numbers are blocked, and verify that the security info on the account is correct.
References:
- Microsoft Authenticator FAQs | Microsoft Support
- Authentication did not complete | Microsoft Support
- Sign in using Microsoft Authenticator | Microsoft Support
- Common problems with two-step verification for a work or school account
- Unable to log into Authenticator app - Microsoft Q&A
- authenticator app issue after changing to a new phone - Microsoft Q&A