I am not able to login to Azure, my old phone is repaired and MFA is failing

Because the old phone cannot be used for MFA, the sign-in methods must be updated or reset before a new device can be added.

For a work or school (Microsoft Entra / Azure AD) account:

1. If another admin exists in the tenant
   • Ask another cloud services/global admin in the tenant to reset the MFA settings for the account:
     1. They sign in to the cloud service portal as admin.
     2. Go to https://account.activedirectory.windowsazure.com/usermanagement/multifactorverification.aspx.
     3. Select the checkbox for the affected user account.
     4. Select Manage user settings.
     5. Select Require selected users to provide contact methods again, then Save.
   • After this, sign in again; the portal will prompt to set up MFA from scratch on the new phone (e.g., Microsoft Authenticator, phone number).
2. If no other admin exists and this is the only global admin
   • This is a tenant lockout scenario. Microsoft’s Data Protection team must help restore access.
   • Contact Microsoft support by phone (Customer service phone numbers - Microsoft Support) and clearly state that access to the global admin account is blocked due to MFA and there is no other admin.
   • The Data Protection team will verify identity and reset access/MFA so that MFA methods can be reconfigured on the new device.
3. If the issue is only that the phone number or device changed but sign-in is still possible via another method
   • After signing in, go to the Additional security verification / Security info page (https://account.activedirectory.windowsazure.com/proofup.aspx?proofup=1).
   • Remove the old phone entry ("Security info type, phone, delete phone").
   • Use Add sign-in method → choose Phone or Authenticator app and follow the prompts to register the new phone.

If the account is a personal Microsoft account (Hotmail/Outlook) and not an Azure AD work/school account, use the personal account security options and two-step verification management described in the MFA troubleshooting article to regain access and then update security info to the new phone.

References:

• Can't use Azure Multi-Factor Authentication to sign in to cloud services after you lose your phone or the phone number changes
• Use a screen reader to set up and troubleshoot multifactor authentication
• "We didn't receive a response" error message when you try to sign in by using Azure Multi-Factor Authentication
• I need to reset my mfa methods - 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
• Azure has blocked myphone number for SMS verification due to a “bad reputation” flag - Microsoft Q&A
• Severity A Situation - Locked out of global admin account (MFA) - business down - Microsoft Q&A