signing in on new phone issues

To sign in to Teams on a new phone when Authenticator and an old secondary email are causing issues, use the following approaches depending on whether this is a personal Microsoft account (Outlook/Hotmail) or a work/school account.

1. If this is a personal Microsoft account (Teams Free / consumer)

1. On a desktop browser where sign-in still works, go to the Microsoft account security page and update your sign-in info:
   • Go to Manage how you sign in to Microsoft: https://account.live.com/names/Manage
   • Add a current email or phone number using Add email or Add phone number.
   • Verify it and select Make primary so it becomes the main sign-in alias.
   • Remove the old secondary email you no longer have access to.
2. If using Microsoft Teams Free on mobile:
   • After updating your account aliases, uninstall Teams from the phone.
   • Reinstall it from the Google Play Store or iOS App Store.
   • Sign in with the updated primary email or phone number.
   This ensures people can no longer search for the old email/number in Teams Free and that the app uses the new sign-in alias.
3. If Authenticator is still requested for sign-in, use any alternative verification method that is still available (SMS, backup email). If no alternative works and this is a personal account, continue using the desktop session where you are still signed in to update your security info as above before trying again on the phone.

2. If this is a work or school (business) Teams account

1. If Authenticator is the only 2FA method and the old email is no longer accessible, contact the organization’s Microsoft 365 administrator and ask them to reset your MFA settings in Microsoft Entra so you can re-register Authenticator on the new phone.
2. If you are the only admin for a business tenant and are locked out, the Microsoft Data Protection team must help verify identity and restore access. In that case, call Microsoft support using the appropriate customer service phone number and request a service ticket for MFA/Authenticator lockout, as described in the moderator guidance in the context.

3. General guidance for Teams sign-in on the new phone

Once account security info is fixed (new email/phone added and verified, MFA reset if needed):

1. Install Microsoft Teams on the new phone.
2. Sign in using the updated primary alias (email or phone number) for the Microsoft account.
3. Complete MFA using the working method (SMS, new Authenticator registration, or backup email).

If sign-in still fails or loops on the phone, first confirm that sign-in and security verification work correctly in a desktop browser; then remove and reinstall Teams on the phone and sign in again with the corrected account details.

References:

• Change your phone number or email address in Microsoft Teams Free
• Adding your phone number to a Microsoft account in Microsoft Teams Free
• Why am I having trouble signing in to Microsoft Teams?
• 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
• Cannot authenticate with E-mail when logging into Microsoft Authenticator(iOS). - Microsoft Q&A