Log in with authenticator app

If the old device is still available, approve the sign-in there first, then remove the old registration.

For a personal Microsoft account:

1. Go to the two-step verification area of your Account Security page.
2. Turn off verification for the old device.
3. Remove the account from the old phone’s Authenticator app if the device is still accessible.

For a work or school account:

1. Go to the two-step verification area of your My Apps page or your organization’s company portal.
2. Turn off verification for the old device.
3. If the old device is still accessible, remove the account from the Authenticator app on that device.

If sign-in prompts are still going to the old phone, that is expected when Authenticator was last used there. In that case:

1. Check the old device and approve the sign-in if possible.
2. Use another verification method such as SMS, if available.
3. Then remove the old device registration.

If the old device is no longer available and this is a work or school account, an administrator might need to require MFA re-registration or remove the existing Authenticator registration. If the tenant has reached the five-device Authenticator limit, sign-in methods can be deleted at https://aka.ms/mysecurityinfo. Warning: deleting a passwordless sign-in method requires another two-factor authentication method to be set up first.

If the goal is to remove the account from the Authenticator app itself:

1. Open Authenticator.
2. Select the account.
3. Tap the Settings gear.
4. Tap Remove account.

To remove all accounts from the app, reset the app data:

• Android: Settings > Apps > Authenticator > Storage or Storage & cache > Clear data > OK
• iOS: Settings > General > Storage > Authenticator > Offload App

Warning: removing accounts or clearing app data cannot be undone, and the device will no longer be usable for sign-in verification.

References:

• Microsoft Authenticator FAQs | Microsoft Support
• How to sign out from Authenticator | Microsoft Support
• Can't set up MFA because five devices are already registered to use an authenticator app