Authenticator login problem

The account is stuck in an MFA loop because the Microsoft Authenticator registration on the device was removed when the app was uninstalled. To recover access, use an alternative sign-in method or have MFA reset by an admin/support, depending on the type of account.

Follow the path that matches the situation:

1. If this is a work or school account and there is an IT admin

• Sign in using any alternative method available on the sign-in screen (SMS, email code, security key, etc.).
• If no alternative method works, contact the organization’s Help desk or Microsoft 365/Entra admin and ask them to:
  • Open Microsoft Entra admin center.
  • Go to Users → All users → [your account] → Authentication methods.
  • Select Require re-register multifactor authentication (or equivalent reset option).
• After the reset, sign in again and re-add the account to Microsoft Authenticator by scanning the new QR code.

2. If this is a work or school account and there is no other admin (you are the only admin)

• This is the “locked-out sole admin” scenario. The documented resolution is to involve the Microsoft Data Protection team via Microsoft Support.
• Call the regional Customer service phone numbers - Microsoft Support and, when prompted by the automated system, clearly indicate:
  • The issue is with Authenticator.
  • The product is Office 365 for business / company account.
  • You are the administrator and there are no other admins.
  • You need a service request and to speak with the Data Protection team to reset MFA on the tenant admin account.
• If unable to reach a live agent, one documented workaround is to:
  • Create a temporary trial Microsoft 365 tenant.
  • Use that tenant’s admin center to open a support ticket explaining that access is needed to a different, existing tenant where you are the locked-out admin.
• After verification, the Data Protection team can reset MFA so the account can be re-registered in Authenticator.

3. If this is a personal Microsoft account and there is no working alternative method

• Use any available alternative method (SMS, email, etc.) if offered on the sign-in page.
• If none work and access is completely blocked, follow the account recovery and password reset flow from the sign-in page and use the “I don’t have any of those” or equivalent option to start recovery.

4. If the app shows “Authentication did not complete” or similar

• Ensure:
  • Microsoft Authenticator is unlocked.
  • Notifications are enabled and not silent.
  • The app is updated to the latest version.
  • The device has working internet and correct date/time.
• If the password is forgotten, use the official Reset your password flow.

If access to the account is still available on another device or browser session, temporarily add or change MFA methods there (for example, add SMS or another app), then sign in on the phone using that method and reconfigure Microsoft Authenticator.

References:

• Authenticator Did Not Complete Login
• Troubleshoot problems with Microsoft Authenticator
• Common problems with two-step verification for a work or school account
• Cannot authenticate with E-mail when logging into Microsoft Authenticator(iOS). - Microsoft Q&A
• How Do I Regain Access to My Account After Losing Access to Microsoft Authenticator? (Urgent Request). - 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