B2C user is experiencing "Phone number has bad reputation, blocking." error suddenly during MFA (Both phone call and SMS options).

Question

We are trying to determine why one of our B2C users is experiencing a "Phone number has bad reputation, blocking." error suddenly during MFA (Both phone call and SMS options). They were able to authenticate via MFA at an earlier date but can no longer due to this error. We cannot find the option in the B2C tenant nor Azure Portal to whitelist the user's phone number to circumvent this error. Is this possible, if so, how is this accomplished?

Also, we currently only provide SMS and Phone Call as our MFA methods.

Answer 1

Hi @Jezeski, Troy J (OIT) , I'm sorry you're having this issue! Unfortunately, there's not much we can do on our end as you can't whitelist phone numbers for MFA. The number's reputation comes from their phone carrier. You would have to ask the user to contact their carrier to resolve the reputation issue. The only other solution would be to use a different MFA method such as Authenticator.

Please let me know if you have any questions and I can help you further.

If this answer helps you please mark "Accept Answer" so other users can reference it.

Thank you,

James