Trouble with Authenticator app

The account is stuck in an authentication loop because the existing multifactor authentication (MFA) method (Microsoft Authenticator on the old phone) is still required, but the new device is not fully registered and there is no working alternative method.

To break the loop, one of these must happen:

1. Use a different verification method

• On the sign-in screen, choose an alternative method such as SMS, phone call, or email code if any are configured (for example, “I don’t have my Authenticator app” or “Use a different verification option”).
• If a different method works, sign in and go to the Security info page for the school/work account and update MFA methods (remove the old Authenticator registration and add the new phone/Auth app).

2. Have the school’s IT/admin reset MFA

• For a school (work or school account), contact the organization’s Help desk or IT administrator and explain that the phone was changed and the Authenticator app was removed.
• Ask them to reset or clear the MFA/authentication methods for the account in Microsoft Entra ID and require re-register multifactor authentication.
• After they reset MFA, sign in again; the account will prompt to set up Authenticator on the new phone from scratch.

3. If the device was lost or reset

• If the old device is unavailable and no alternative method exists, only the organization’s Help desk/IT admin can clear the MFA settings so that registration can be redone.

If repeated sign-in attempts have been made, Microsoft Entra multifactor authentication may temporarily block further attempts as unusual activity. In that case, wait before trying again, or use a different MFA method if available.

References:

• Common problems with two-step verification for a work or school account
• Microsoft Authenticator FAQs
• Authenticator app not sending code to my email - Microsoft Q&A
• 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
• I need to reset my mfa methods - Microsoft Q&A
• Requesting a Tenant Admin MFA Reset - Microsoft Q&A

Hello @White, Skylor

I understand that you are stuck in a loop and cannot access your school email. In this case, I strongly recommend that you contact your school’s IT Admin for support. They are the appropriate team to help you reset your account and resolve this issue quickly by following the guidance below.

(The IT department at your school includes global administrators who have full control over all user accounts in your school tenant.)

In this case, as you are using university account, the only way to regain access is to contact your "IT administrator or Global admin" and request a phone number update in the Microsoft Entra admin center.

In the Entra admin center, an administrator can set user accounts to require a re-enrollment of multi-factor authentication (MFA). Ask your administrator to follow the steps shown in the following article:

Manage user authentication methods for Microsoft Entra multi-factor authentication

• Sign in to Microsoft Entra - Microsoft Entra admin center
• User -> all users. Select the user you want to act on, and then select "Authentication methods". then select "Require multi-factor authentication re-registration".

Require re-enrollment MFA: This disables all previous authentication methods. You'll then be prompted to set up a new MFA authentication method the next time you try to sign in, so you can add a new authenticator app.

*Note:

• Please note that in this case, you only need to find the global admin of your organization’s tenant. They are the ones who can help you regain access to your account.
• The global admin is usually someone in your school’s IT team or a system administrator. They manage Microsoft 365 settings, licenses, and security.
• Most schools have a helpdesk or IT support email. You can contact them to confirm who the global admin is.

Wishing you all the best!

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