Not able to login with Authenticator - no other option available

Since Authenticator is the only sign-in option and it is not working, recovery depends on whether this is a work/school (Microsoft Entra / Microsoft 365) account or a personal Microsoft account.

1. If this is a work or school account and there is an IT admin
   • Contact the organization’s IT administrator and ask them to reset multifactor authentication (MFA) for the account.
   • The admin can go to Microsoft Entra admin center → Users → select the user → Authentication methods → Require re-register multifactor authentication. After this reset, sign-in will prompt to set up Authenticator again.
2. If this is a work or school account and there is no other admin (sole admin locked out)
   • A Microsoft Data Protection team request is required.
   • Call Microsoft Support using the regional customer service phone number and ask to open a ticket with the Data Protection team to reset the admin’s authentication methods for the tenant. Be clear that this is a business/tenant admin account and that there is no other administrator.
   • If reaching an agent is difficult, create a temporary Microsoft 365 trial tenant, sign in to its Admin Center, and open a support ticket from there requesting Data Protection assistance for the original locked tenant.
3. If this is a personal Microsoft account
   • Use the account recovery and password reset options (for example, “Forgot password” and security info recovery) to regain access without Authenticator.
   • If alternative methods (email/SMS) are still configured and working, use them to sign in and then remove and re-add Authenticator.

If none of the above paths are available and Authenticator is the only configured method, direct support from Microsoft (for personal accounts) or the Data Protection team (for business tenants) is required to regain access.

References:

• Troubleshoot problems with Microsoft Authenticator
• Sign in using Microsoft Authenticator
• Enable passwordless sign-in with Authenticator
• I cant log in to my business account because it is requiring Authenticator app which I do not have - 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
• Requesting a Tenant Admin MFA Reset - Microsoft Q&A