Switched to a new phone and no longer have my old phone but Authenticator App isn’t letting me login into my work email.

Because the old phone with Microsoft Authenticator is no longer available, the current sign-in is stuck asking for approval in an app that cannot be accessed. To get back into the work account and email, the authentication methods must be reset or an alternative method must be used.

Use these options, depending on what is available for the work account:

1. Try an alternative verification method

• On the sign-in screen where the number is shown and approval in Authenticator is requested, look for a link such as “I don’t have my Microsoft Authenticator app” or “Sign in another way”.
• Choose another method if it exists (for example, SMS to a mobile phone or a call to an office phone) and complete sign-in that way.
• If this works, go to the Security info page for the work or school account and update the sign-in methods so a new phone and Authenticator can be added and old methods removed. See: Common problems with two-step verification for a work or school account for how to review and update security info.

2. If no alternative method works

• If there is no working SMS, phone, or email method, the work account’s MFA settings must be reset by an administrator:
  • An IT/admin for the organization can go to the Microsoft Entra admin center, open the user account, and use Require re-register multifactor authentication so that MFA methods can be set up again on the new phone.
  • After the reset, sign in again; the account will prompt to set up Microsoft Authenticator on the new phone using a QR code.

3. If this is the only admin account in the organization

• If this is a business/organization tenant and this work account is the only administrator, Microsoft’s Data Protection team must be involved to regain access:
  • Contact Microsoft support by phone (Customer service phone numbers - Microsoft Support) and request help for being locked out due to Microsoft Authenticator on a replaced phone.
  • The support process verifies identity and can help restore access to the admin account so MFA can be reconfigured.

Until an alternative method is used or an admin resets MFA, the sign-in prompt will continue to ask for approval in the old Authenticator app and access to work email will remain blocked.

References:

• Common problems with two-step verification for a work or school account
• Use a screen reader to set up and troubleshoot multifactor authentication
• 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
• I need to reset my mfa methods - Microsoft Q&A