Phone Factor - "mfa-phone-challenge" vs. "mfa-sms-challenge"

Overview

After enrolling in MFA using the phone factor, on subsequent logins, some users will see the mfa-phone-challenge, while others will see the mfa-sms-challenge when prompted for MFA. This article explains what could cause this behavior.

Applies To

  • Multifactor Authentication
  • Phone factor
  • Phone Challange vs. SMS Challange

Solution

When users first enroll in MFA using the phone factor, they see the mfa-phone-enrollment screen.

  • If they choose to enroll using a Voice call first, on subsequent logins, they will see the mfa-phone-challenge screen, giving them the option to choose between sms and a call to deliver the code.
  • If the user chooses to enroll using a Text message first, on subsequent logins, they will see the mfa-sms-challenge screen, with a link to “Get a call” if they prefer so.

Each screen is described in this document. Please check it out for further details.