Authenticator app issues

To disconnect Microsoft Authenticator from a work account when the app on the new phone is not working, the account’s sign-in methods must be reset from outside the app. This cannot be done only from the new phone.

Use these options in order:

1. Try an alternative sign-in method (if one exists)
   When prompted for the Authenticator code on the PC:
   1. On the sign-in screen, tab or click until the option like “Sign in another way” appears, then select it.
   2. Choose another method (for example, SMS, office phone, or email) if it is listed, and complete sign-in using that method.
   3. After signing in, go to the Security info page for the work account and update or remove the Microsoft Authenticator method, then re-add it on the new phone.
   If no alternative method is configured, this option will not appear and an admin must reset MFA.
2. If this is a work/school account and there is an IT/admin team
   Ask the organization’s IT help desk or Microsoft 365/Entra administrator to reset MFA for the account:
   1. Admin signs in to the Microsoft Entra admin center.
   2. Goes to Identity → Users → All users.
   3. Selects the user account.
   4. Opens Authentication methods.
   5. Clicks Require re-register multifactor authentication.
   After this reset, the next sign-in will prompt to set up Microsoft Authenticator again on the new phone (scan QR code, approve sign-in, etc.), effectively disconnecting the old Authenticator registration.
3. If this is a work/school account and there is no other admin
   If the account is the only administrator in the tenant and there is no one else who can reset MFA:
   • Contact Microsoft via the regional Customer service phone numbers - Microsoft Support and request the Data Protection team to reset MFA for the tenant admin account.
   • During the call, clearly state:
     • This is an Office 365/Microsoft 365 for business work account.
     • The phone was replaced and the Microsoft Authenticator app on the old phone is no longer available.
     • The account is the only administrator and cannot pass MFA.
   • The Data Protection team will verify identity and can reset the MFA configuration so Authenticator can be set up again on the new phone.
4. General Authenticator troubleshooting on the new phone (after MFA is reset)
   Once an admin or Microsoft has reset MFA and sign-in is possible again, ensure the new phone is correctly set up:
   • Install the latest Microsoft Authenticator version and enable App updates.
   • Turn off battery optimization for Authenticator and ensure Show notifications is enabled in Notification Settings.
   • Make sure device date/time and network (Wi‑Fi or mobile data) are working correctly.

There is no way from the user side to “disconnect” Microsoft Authenticator from a work account without either using an alternative sign-in method or having an admin (or Microsoft Data Protection) reset the MFA/Authenticator registration.

References:

• Use a screen reader to set up and troubleshoot multifactor authentication
• Troubleshoot problems with Microsoft Authenticator
• Microsoft authenticator sending me into a spiral - Microsoft Q&A
• I have a Micrsoft business account and I am the admin and the only user registered under this account. I can't log in because i have replaced my phone and the authenticator doesn't work. - Microsoft Q&A
• Microsoft Authenticator app doesn't show 6-digit OTP code - Microsoft Q&A
• Requesting a Tenant Admin MFA Reset - Microsoft Q&A