Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
If no alternate sign-in method works, have another authorized administrator require MFA re-registration for the locked account; if this is the tenant’s only administrator, contact Microsoft business support for tenant-admin account recovery.
1. Try an existing alternative sign-in method
At the authentication prompt:
- Select Sign in another way or Other verification options.
- Use any previously registered method, such as SMS, voice call, security key, or another Authenticator device.
- After signing in, open Security info, add a working method, and remove the broken Authenticator registration.
Microsoft recommends using a different registered method when the Authenticator device is unavailable.^1^
2. If another administrator can sign in
For an administrative account, use another Global Administrator or appropriately authorized Privileged Authentication Administrator. Microsoft recommends retaining at least a Privileged Authentication Administrator so a locked-out Global Administrator can be recovered.^2^
That administrator should:
- Sign in to the Microsoft Entra admin center.
- Go to Entra ID → Users.
- Select the locked administrator.
- Open Authentication methods.
- Select Require re-register MFA.
This deletes the user’s registered Authenticator apps, phone numbers, and software OATH methods. At the next sign-in, the user is prompted to register MFA again.^3^
If available in your tenant, the administrator can instead issue a Temporary Access Pass (TAP). In Authenticator, select Add account → Work or school account → Sign in, then authenticate with the TAP to register the new app.^4^
3. If you are the only administrator
Actions inside Entra or Microsoft 365 cannot be used because they require an authenticated administrator. Contact Microsoft Support, enter the issue, select Get Help, and then Contact Support.[^5^](https://support.microsoft.com/accounts-billing/subscriptions/[Subscription ID] "Microsoft 365 for business")
Describe the case as:
Sole Global Administrator locked out of the Microsoft 365/Entra tenant because the only registered MFA method, Microsoft Authenticator, is unavailable. Tenant-admin account recovery and ownership verification are required.
Be prepared to prove tenant ownership. Support cannot simply send verification codes or change account details without the required verification.
If Authenticator still opens but prompts are failing
Before resetting its registration, check that the phone has network connectivity and Authenticator notifications are enabled. Update Authenticator from the device’s app store and restart the phone. If the issue persists, capture logs using Authenticator → Settings → Send Feedback.^6^
Avoid repeated sign-in attempts; Microsoft Entra can temporarily prevent further attempts after detecting unusual or repetitive activity.^1^
References
- Common problems with two-step verification for a work or school account
- About administrator roles in the Microsoft 365 admin center
- Manage user authentication methods for Microsoft Entra multifactor authentication
- Configure Temporary Access Pass to register passwordless authentication methods
- [Microsoft 365 for business](https://support.microsoft.com/accounts-billing/subscriptions/[Subscription ID])
- Troubleshoot problems with Microsoft Authenticator | Microsoft Support