Support Request: Phone Number Blocked (BadReputation) – Error 399287

Question

Support Request: Phone Number Blocked (BadReputation) – Error 399287

Roar Håkonsen 20

Hello Microsoft Support,

I need assistance with an issue where one of our Global Administrators cannot receive SMS verification codes due to a reputation block on their phone number.

Based on Microsoft guidance, this appears to be a backend anti‑fraud reputation block that must be cleared by engineering. Please escalate this case to the appropriate team for a PhoneReputation unblock.

This issue is preventing recovery of a Global Administrator account, so we would appreciate expedited handling.

Thank you!

Rukmini 44,000 Reputation points Microsoft External Staff Moderator

2026-02-26T10:39:39.5+00:00

Hello Roar Håkonsen,

Please share the details over the private messages so that we can assist you further.
Roar Håkonsen 20 Reputation points

2026-02-26T12:00:12.54+00:00

Thx for the rapid help!

//Roar
Rukmini 44,000 Reputation points Microsoft External Staff Moderator

2026-02-26T12:01:05.6366667+00:00

Roar Håkonsen If the resolution was helpful, kindly take a moment to click on and click on Yes for was this answer helpful. And, if you have any further query do let us know.

Answer accepted by question author

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Rukmini 44,000 Reputation points Microsoft External Staff Moderator

2026-02-26T10:39:39.5+00:00

Hello Roar Håkonsen,

Please share the details over the private messages so that we can assist you further.
Roar Håkonsen 20 Reputation points

2026-02-26T12:00:12.54+00:00

Thx for the rapid help!

//Roar
Rukmini 44,000 Reputation points Microsoft External Staff Moderator

2026-02-26T12:01:05.6366667+00:00

Roar Håkonsen If the resolution was helpful, kindly take a moment to click on and click on Yes for was this answer helpful. And, if you have any further query do let us know.

Answer 1

Hello Roar Håkonsen,

Thank you for sharing your details(user's email address, tenant id, phone number, country code and country) with us over Private Message

I have reached out to the engineering team to unblock MFA for your account. They have now unblocked it from the backend and removed the bad reputation on it. You should be able to log in to the Azure Portal without any issues.

Please try logging in and check if you can complete SMS authentication without any errors. Let me know if you encounter any issues.

As a best practice, I recommend registering the Microsoft Authenticator method for your account instead of relying on SMS. SMS and voice call authentication methods are more vulnerable to IRSF attacks (telephony fraud) and are generally less secure.

For better practice, I recommend registering with Microsoft Authenticator method to your account instead of SMS method as these SMS/Voice telecom auth methods are susceptible to IRSF attacks telephony fraud.

I hope this information is helpful. Please feel free to reach out if you have any further questions.

If the resolution was helpful, kindly take a moment to click on and click on Yes for was this answer helpful. And, if you have any further query do let us know.

Roar Håkonsen 20 Reputation points

2026-02-26T12:24:20.27+00:00

Thx for the help :-)