How to fix authenticator app

Access to the Microsoft Authenticator app itself cannot be “recovered” if the original second factor (old phone, recovery codes, or another MFA method) is no longer available. Instead, the MFA methods for the university (work/school) account must be reset by the organization, and then the app must be set up again from scratch.

Use these paths depending on what is still accessible:

1. Try any alternative MFA method

• When prompted for verification, look for an option such as “Sign in another way”.
• If any other method (SMS, office phone, email code) is listed and still works, use it to sign in.
• Once signed in, go to the Security info / Authentication methods page for the work/school account and:
  • Remove the old Authenticator registration.
  • Add Microsoft Authenticator again on the new phone by following the prompts.

2. If no alternative method works

• For a university/work account, contact the university’s IT help desk or support desk.
  • Explain that the phone was changed, Authenticator is no longer accessible, and no recovery codes or other MFA methods are available.
  • Ask them to clear/reset MFA settings for the account.
• After the help desk clears the settings, the next sign-in will prompt to register MFA again; at that point, install Microsoft Authenticator on the new phone and complete setup.

3. If sign-in attempts are blocked or codes not received

• Repeated failed attempts can cause temporary blocks on MFA or verification codes. In that case, wait and try again later, or use a different MFA method if one exists.
• If SMS or email codes are also not arriving, the help desk must review and correct the security info on the account.

4. For the personal Microsoft account linked to the university email

• Once access to the university email and Authenticator is restored as above, use that access to update the personal account’s security info.
• Add multiple methods (Authenticator, a personal phone number, and a personal email) to avoid lockout in future.

If the university/work account is the only way to verify the personal account and cannot be recovered, the personal account’s 2-step verification cannot be completed until the university account’s MFA is reset by the organization.

References:

• Common problems with two-step verification for a work or school account
• Use a screen reader to set up and troubleshoot multifactor authentication
• Troubleshoot problems with Microsoft Authenticator
• Work or school account help
• I can't sign in after multiple attempts
• I need to reset my mfa methods - Microsoft Q&A
• Microsoft authenticator sending me into a spiral - Microsoft Q&A
• Requesting a Tenant Admin MFA Reset - Microsoft Q&A