AAD B2C MFA Error when sending a new code

Question

When verifying the phone number for MFA, a code is sent to the uesr's mobile phone. If they then request a new code, an error message is displayed:

"You hit the limit on the number of text messages. Try again shortly.​"

Steps:

1. User signs in or signs up (text message with a code is sent to their number for MFA)
2. User clicks "send a new code".
3. Error message is displayed and user cannot perform any action.

I have seen information saying there is a limit of 100 SMS codes/phone number/day, but this has not been reached. Are there any other limitations that might be causing this, and are we able to modify them?

Error message

Answer 1

• If you are facing this issue, then I would suggest you try again after a few minutes of time as Microsoft may have limited the repeated authentication attempts that are performed by the same user or organization in a short period of time. Also, would suggest you check for the below line of code in your Azure AD B2C custom policy and remove that from the policy as its removal will not make the ‘You hit the limit on the number of text messages. Try again shortly’ error to display again.

In the ‘localized strings’ section, find the below line and remove it. You should find the below section in ‘Signuporsignin.xml’ file: -

 <LocalizedResources Id="api.phonefactor.en">
   <LocalizedStrings>
       .......
       ......
      ......
  <LocalizedString ElementType="UxElement" StringId="error_sms_throttled">You hit the limit on the number of text messages. Try again shortly.</LocalizedString>
    ......
    .......
    ........   
   </LocalizedStrings>
   </LocalizedResources>

For more details on this, please refer to the link below: -

https://learn.microsoft.com/en-us/azure/active-directory-b2c/localization-string-ids#phone-factor-authentication-page-user-interface-elements