I am trying to fix my MFA and in doing so I have locked my business account

Because the account is a business/tenant account and there is only one administrator who is now locked out by MFA, recovery must go through Microsoft’s Data Protection team. Local changes or self-service options will not work once locked out as the sole admin.

Follow these steps:

1. Try any alternative MFA/sign-in methods first (if available)
   • If another verification method was ever configured (SMS, phone call, different app, security key), use “Sign in another way” on the sign-in screen and complete sign-in that way.
   • If this works, go to the Security info / Additional security verification page and update or remove the old phone/app and add the new phone and Microsoft Authenticator again, as described in:
     • Change your two-step verification method and settings
     • Download and install the Microsoft Authenticator app
2. If no alternative method works and you are locked out as the only admin
   In this situation, only Microsoft’s Data Protection team can reset the admin’s MFA:
   • Call the Customer service phone numbers - Microsoft Support line listed in the documentation.
   • When the IVR/automated system asks questions, answer along these lines to reach the correct team:
     • Problem type: say “Authenticator”.
     • Product: “Office 365 for business”.
     • Account type: “For companies” (not education/personal).
     • When asked if there is another administrator: “No”.
     • When asked if a service request is needed: “Yes, I need to create a ticket and speak with the Data Protection team”.
   • Clearly state that:
     • This is a business/tenant account.
     • The caller is the only global administrator.
     • MFA is blocking access after a phone change and Authenticator reset.
   • The frontline agent should open a Data Protection ticket. That team will then verify identity (business documentation, tenant details, etc.) and perform an admin MFA reset so access can be restored.
3. If phone support cannot be reached or will not route correctly
   As an alternative path used in similar cases:
   • Sign up for a new trial Microsoft 365 tenant (a completely separate environment) using the public Microsoft 365 Business/Enterprise trial link in the documentation.
   • After creating that new tenant, go to the Microsoft 365 Admin Center for the new tenant and open a support ticket from there.
   • In the ticket, clearly explain that:
     • The issue is with a different, existing tenant.
     • The original tenant’s only global admin is locked out by MFA after a phone change.
     • Provide the locked tenant’s domain and admin UPN and request escalation to the Data Protection team to reset MFA on the original tenant.
   • This temporary tenant is only for contacting support; it does not give access to data in the original tenant. Remember to cancel the trial once the original tenant is recovered.
4. After Data Protection resets MFA
   • Sign in again to the original tenant when instructed.
   • Reconfigure MFA methods immediately: add the new phone number, install and register Microsoft Authenticator on the new phone, and consider adding at least one backup method (phone/SMS/alternate app) so a future device change does not cause another lockout.

These are the supported recovery paths when a sole business/tenant administrator is locked out due to Microsoft Authenticator/MFA issues.

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 Microsoft verification code issues
• "Account verification system is having trouble" error message when you try to sign in by using a work or school account
• 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
• I need to reset my mfa methods - Microsoft Q&A
• Requesting a Tenant Admin MFA Reset - Microsoft Q&A
• Severity A Situation - Locked out of global admin account (MFA) - business down - Microsoft Q&A
• Microsoft authenticator sending me into a spiral - Microsoft Q&A