authenticator app does not work properly on my new smartphone

For Teams access through an organization, the issue is typically that the old device is still registered for MFA, so notifications and codes are tied to that old registration rather than the new phone.

Use these steps to fix it:

1. Make sure Authenticator can receive notifications on the new phone
   • Open the Microsoft Authenticator app.
   • Go to Settings → Notification Settings and ensure Show notifications is turned on.
   • Turn off battery optimization for Authenticator in Settings so it can sync in the background.
   • Ensure the phone has a working internet connection (try switching between Wi‑Fi and mobile data) and that Airplane mode is off.
   • Confirm the device date and time are correct and the app is updated to the latest version.
2. Confirm push notifications are enabled for the account type
   • For a personal Microsoft account, re‑register the account in Authenticator:
     • In Authenticator, choose Add account → Personal Microsoft account and sign in again.
   • For a work or school (organization) account, the organization controls whether push notifications are allowed. If they are disabled by the admin, only codes will work.
3. Remove the old device registration so notifications stop going there
   • If the Teams account is a personal Microsoft account:
     • Sign in to the two‑step verification area of the Account Security page.
     • Turn off verification for the old device so that only the new phone remains registered.
   • If the Teams account is a work or school account:
     • Go to the two‑step verification area of either the My Apps page or your organization’s company portal.
     • Turn off verification for the old device.
4. Re‑add the work/school account to Authenticator
   • From a browser where Teams sign‑in still works, open the security/MFA settings page used by the organization (for example, Security info or Additional security verification page if they use Microsoft 365).
   • Remove the old Authenticator method for that account.
   • Add a new sign‑in method and choose Authenticator app.
   • Scan the new QR code with the Authenticator app on the new phone.
5. If still locked out of the organization account
   • Contact the organization’s IT admin and ask them to reset the MFA methods for the account. They can clear the old Authenticator registration so the new device can be set up.

These steps ensure the old phone is fully unregistered and the new phone is the only device receiving Teams/MFA prompts.

References:

• Troubleshoot problems with Microsoft Authenticator
• Microsoft Authenticator FAQs
• Use a screen reader to set up and troubleshoot multifactor authentication