Accessing work email using authenticator

Question

I have had a new phone and have tried to log into authenticator to access my work email account, which I previously accessed using authenticator without issue. Authenticator is asking me to log in using my work email but is now saying that it does not exist in the system. It did two days ago though and colleagues are not having any problems using authenticator to log in

Answer 1

The behavior indicates an account or MFA configuration issue rather than a general Authenticator problem, especially since colleagues can still sign in.

Use these steps and checks:

1. Confirm the account still exists and is active
   • Since the app now says the work email “does not exist,” first confirm with the organization’s IT/Entra ID admin that:
     • The account has not been disabled, deleted, or renamed.
     • The sign-in name (UPN) has not changed (for example from ******@company.com to another domain).
2. Try signing in using another MFA method
   • If any other verification methods are configured (SMS, phone call, alternate email, security key, Windows Hello, etc.), use those to sign in to Microsoft 365 in a browser.
   • Once signed in, go to the Security info / Additional security verification page and review or reconfigure the MFA methods for the account.
3. If locked out because only Authenticator was configured
   • This is the “spiral” situation where Authenticator is required to add Authenticator.
   • For a work/school account, the fix must be done by an administrator:
     • Ask the organization’s Microsoft 365/Entra ID admin or Help desk to reset the MFA settings for the user account.
     • In Entra Admin Center they can use the “Require re-register multifactor authentication” option so that, on next sign-in, the account can be set up again in Microsoft Authenticator on the new phone.
   • If the user is the only admin on the tenant and is locked out, the admin must contact Microsoft support (Data Protection team) by phone to have MFA reset, as described in the referenced Q&A threads.
4. Re-add the work account to Microsoft Authenticator after MFA reset
   • Once MFA is reset and sign-in works in a browser:
     1. Install Microsoft Authenticator on the new phone.
     2. From a browser session where already signed in, go to the Security info / Additional security verification page.
     3. Choose to add “Microsoft Authenticator” as a sign-in method.
     4. Scan the QR code with the app and complete the verification.
5. If the app still reports the email “does not exist”
   • This message typically means the identity platform is not recognizing that sign-in name for this tenant:
     • Double-check spelling and domain.
     • Confirm with IT that the account is in the correct tenant and not moved or removed.
     • If the account was recently changed (renamed, domain switched), use the new sign-in name in Authenticator.

If none of the above works and there is no alternative MFA method, the only supported resolution for a work/school account is for the organization’s IT admin (or Microsoft Data Protection team if the user is the sole admin) to reset MFA and confirm the account status.

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References:

• Troubleshoot problems with Microsoft Authenticator
• How to add your accounts to 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
• Microsoft authenticator sending me into a spiral - 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
• Requesting a Tenant Admin MFA Reset - Microsoft Q&A