Microsoft Authenticator Isn’t Sending Sign-In Prompts to My New iPhone

If the iPhone 13 was set up as a new device, the Authenticator accounts and registration data from the iPhone 12 probably did not transfer. A backup or direct phone-to-phone migration during setup may have copied them, but reinstalling the app afterward usually is not enough. You will likely need to sign in to your Microsoft account security settings and register the iPhone 13 again by scanning a newly generated QR code. Keep the iPad available until the new device is confirmed to work.

Since you can still approve sign-ins on the iPad, use that access to add another verification method and register the new phone. If the account is managed by your college, some Authenticator settings may be controlled by its administrator, so the school’s account administrator or Microsoft support may need to reset the old registration and issue a new setup process.