Add phone number as a sign in option

The phone-number option cannot be enabled if it is absent from your personal Microsoft account’s security-method list; Microsoft is phasing out SMS for authentication and recovery, so add a verified recovery email, Microsoft Authenticator, or a passkey instead.^1^

Add an available security and recovery method

1. Open the Microsoft account Security page:
   https://account.microsoft.com/security
2. Sign in with the affected Hotmail account.
3. Select Manage how I sign in.
4. Select Add a new way to sign in or verify.
5. Choose one of the methods displayed:
   • Email address for account verification and recovery.
   • Microsoft Authenticator for verification, including when the device is offline.
   • Passkey to sign in using your device’s face, fingerprint, or PIN.
6. Complete the confirmation prompt and select Next.

If Phone is offered, you can select it and add your current mobile number. A VoIP number cannot be used for sign-in or verification codes.^2^

If Phone is not offered, there is no account setting that restores it. Microsoft is replacing SMS with verified email and passkeys because SMS is vulnerable to phishing and SIM-swap attacks.^3^

Phone sign-in versus account recovery

These are separate uses:

• A security method verifies identity and helps recover the account.
• A phone-number alias is a username that can be used to sign in.

Adding recovery information does not necessarily make the telephone number a sign-in username. If you are specifically adding the number as an alias and Microsoft reports that it belongs to another account, select Transfer when offered. If Transfer is unavailable because the number was used recently with another Microsoft account, Microsoft advises trying again after 30 days or using another number.^4^

If none of the existing security methods works

At the Verify your identity screen:

1. Select I don’t have any of these.
2. Follow the prompts to replace your security information.
3. After all security information is replaced, a 30-day waiting period applies before you can sign in.

If at least one existing method still works, use it to sign in, add a new available method first, and then remove the obsolete number. Avoid replacing every method simultaneously.

If SMS remains available but codes do not arrive, stop repeated requests because they can trigger a temporary block. Try another registered method and allow at least 24 hours; some blocks can take up to one week to clear. Microsoft support cannot send verification codes or directly change protected account details.^2^

References

1. Microsoft account security info & verification codes | Microsoft Support
2. Troubleshoot Microsoft verification code issues | Microsoft Support
3. Microsoft to stop sending SMS codes for personal accounts
4. Help with reusing phone numbers in a Microsoft account | Microsoft Support