Microsoft is discontinuing support for SMS in specific sign-in scenarios. This includes sign-ins from new devices and those that need multi-factor authentication (MFA).
The reason behind this move is to step up security and minimize the chances of unauthorized access.
Typically, the concern arises because employees might not want to use their personal mobile devices to verify their access.
Customers have the option to establish a conditional access policy to reduce the frequency of MFA prompts when they’re in trusted locations. To do this, you’ll need at least one Azure AD P1 (Microsoft Enterprise ID P1), Office 365 E3 Plan, or Office 365 Business Premium subscription.
Another choice is to get a FIDO2 key or a FIDO2-compliant pass for each user. If you encounter any difficulties while setting up MFA using these methods, feel free to reach out to us for assistance.