If you are having issues with SMS verification when setting up multi-factor authentication for Microsoft 365 sign-in, you should ensure that your phone number is entered correctly, and that your carrier is not blocking the SMS messages.
Home > KB > Accounts & MFA > Multi-Factor Authentication (MFA) > How can I troubleshoot issues with SMS verification when setting up multi-factor authentication for Microsoft 365 sign-in?
If you are having issues with SMS verification when setting up multi-factor authentication for Microsoft 365 sign-in, you should ensure that your phone number is entered correctly, and that your carrier is not blocking the SMS messages.