Cannot sign back into authenticator app

There is no way to bypass Microsoft Authenticator if it is the only verification method and the old phone is unavailable. The account’s MFA must be reset or an alternative sign-in method used.

Use the path that matches the type of account:

1. Work or school account (Microsoft 365 / Entra ID)

• If there is another admin in the organization:
  1. Ask the admin to go to Microsoft Entra admin center → Users → All users → select the user → Authentication methods.
  2. Use the option to require re‑registering multifactor authentication / clear MFA methods so that sign-in will prompt for fresh setup on the new phone.
• If there is no alternative method on the account and no other admin can reset MFA:
  • The tenant’s global admin must contact Microsoft support and have the Microsoft Data Protection team reset the admin’s MFA. This is the only supported way when the sole admin is locked in an “endless MFA loop.”
  • The documented pattern is:
    • Call the regional Microsoft customer service phone number (see “Customer service phone numbers - Microsoft Support” in the referenced answers).
    • In the IVR/agent conversation, clearly state this is an Office 365 for business / company account, that the caller is the administrator, and that there are no other admins.
    • Ask to open a service request and escalate to the Data Protection team to reset MFA for the locked admin account.
  • If support cannot be reached from the locked tenant, a temporary trial tenant can be created only to open a support ticket, as described in the referenced Q&A answers. This does not give access to data in the original tenant; it only provides a channel to contact support.

Once Microsoft resets MFA or an admin clears the user’s MFA methods, sign-in will succeed and the Authenticator app can be set up again on the new phone (scan the QR code when prompted during sign-in).

2. Personal Microsoft account (Outlook.com, Hotmail, etc.)

• If locked out because Authenticator is the only method and the backup cannot be restored:
  • Use the Microsoft account sign-in helper to regain access to the Microsoft account that was used as the backup/recovery account for Authenticator. Sign-in helper
  • If backup cannot be accessed, Authenticator credentials cannot be restored; accounts must be re-added manually after access to each service is recovered via their own recovery flows.

3. General Authenticator restore notes

• Restoring Authenticator from backup only restores:
  • For Microsoft work or school accounts: the account name; sign-in is still required again after restore.
  • For Microsoft personal accounts with passwordless sign-in: only the account name; sign-in is required again.
  • For OTP-only accounts (e.g., some third-party services): the OTP configuration.
• If “Restore from backup” or “Begin recovery” is not visible in the app, all existing accounts in Authenticator must be removed or signed out before restore is available.

If none of the above options (alternative MFA method, another admin, or Microsoft Data Protection support for a sole admin) is available, there is no supported way to get back into the Authenticator-based MFA for that work/school tenant; the tenant owner must work with Microsoft support to regain access.

References:

• Restore account credentials from Microsoft Authenticator
• Common problems with two-step verification for a work or school account
• Use a screen reader to set up and troubleshoot multifactor authentication
• How Do I Regain Access to My Account After Losing Access to Microsoft Authenticator? (Urgent Request). - Microsoft Q&A
• Cannot authenticate with E-mail when logging into Microsoft Authenticator(iOS). - 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