Can't set up MS authenticator on iphone

For a personal Microsoft account on iPhone, the app setup is done by starting from the Microsoft account Security page, not by typing the email directly in Authenticator.

Use this path:

1. On a browser, sign in to your Microsoft account Security page: https://account.microsoft.com/security
2. Select Manage how I sign in.
3. Select Add a new way to sign in or verify.
4. Choose Use an app.
5. If Authenticator is already installed, select Set up a different Authenticator app and then Next to show the QR code.
6. On the iPhone, open Microsoft Authenticator, tap the plus icon.
7. Select Personal account > Scan a QR Code.

If scanning the QR code on the same phone is the problem, use the fallback method from the setup page:

1. On the PC/browser setup page, select I can't scan the bar code.
2. In Authenticator on the iPhone, choose Enter code manually.

Important points for the iPhone scenario:

• Face ID on the phone is not the same as adding the account to Authenticator. It can be used later for sign-in in supported flows, but the account still must first be registered in Authenticator from the Microsoft account security setup.
• If this is the first time using Authenticator, allow camera access when prompted. If camera access is denied, manual code entry is still supported.
• Make sure Authenticator is updated to the latest version. QR scanning requires the latest version, and versions older than 12 months are not supported.
• If the app is not behaving correctly, check Settings in Authenticator and make sure notifications are enabled, battery optimization is turned off, the device date/time is correct, and if a VPN is active, try disconnecting it.

Since SMS codes are not reliable while overseas, the best path is to complete setup using the Security page + QR code/manual code flow above.

References:

• How to add your accounts to Microsoft Authenticator
• Troubleshoot problems with Microsoft Authenticator
• Download Microsoft Authenticator