Can’t login to Microsoft authenticator or outlook

Because both Microsoft Authenticator and Outlook are locked behind the same multifactor authentication (MFA) methods, the loop can only be broken by using an alternative sign-in method or having MFA reset from the account side.

Use any alternative verification method that is already configured:

1. If this is a personal Microsoft account and another security method (SMS, backup email, or a different phone) is configured, choose that option on the sign-in screen instead of Authenticator or Outlook.
2. If none of the listed methods are accessible, select I don't have any of these when prompted for a verification method and follow the on-screen account recovery process to update security info and regain access.
3. After recovery, go to the Additional security verification or Security info page and add the new phone/Auth­enticator as a sign-in method, then remove the old phone entry so the loop does not recur.

If this is a work or school account:

1. Try any other MFA method already configured (SMS, phone call, security key, etc.).
2. If all methods are inaccessible and multiple sign-in attempts have already been made, wait and try again or use a different MFA method if available, because repeated attempts can be blocked by Microsoft Entra multifactor authentication.
3. If still unable to sign in, contact the organization’s IT administrator or Help desk and ask them to reset or clear MFA settings in Microsoft Entra ID so that MFA registration can be performed again on the new phone.

If Authenticator shows “Authentication did not complete” or similar when trying to re-add the account on the new phone, ensure:

1. The Microsoft Authenticator app is unlocked.
2. Notifications are enabled for Authenticator.
3. The app is updated to the latest version.
4. The device has a working internet connection and correct date/time.

Once access to the account is restored, reinstall and reconfigure Microsoft Authenticator on the new phone and verify at least one backup method (SMS or email) is present so that future device changes do not cause another lockout.

References:

• Troubleshoot problems with Microsoft Authenticator
• Use a screen reader to set up and troubleshoot multifactor authentication
• Common problems with two-step verification for a work or school account
• Troubleshoot Microsoft verification code issues
• Authenticator locked and cannot access at all after replacing phone - 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 sending me into a spiral - Microsoft Q&A