How to receive an sms message if error 399287 appear

Question

How to receive an sms message if error 399287 appear

Abdul Karim Al Khayari 0

I am the administrator of a Microsoft 365 business tenant and I am currently unable to access the Microsoft 365 Admin Center / Microsoft Entra Admin Center.

The authentication process fails with:

Error Code: 399287 Request ID: [Moderator note: Personally Identifiable Information removed] Timestamp: 2026-09-14T06:09:34Z

The problem occurs during MFA / phone verification.

I understand that error 399287 may indicate that the phone number has been blocked by Microsoft Entra Phone Reputation / fraud protection.

This is an administrator account and I cannot access the Admin Center to create a normal support request.

I have already tried Microsoft telephone support, but I have not been able to reach the appropriate technical support team.

I need assistance from the Microsoft Data Protection / Tenant Recovery / Entra authentication team to review and remove the MFA phone reputation block.

Please contact me through private message if you need my tenant ID, administrator email address, affected phone number, country, screenshots, or proof of tenant ownership.

Thank you.

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1 answer

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Answer 1

Hi @Abdul Karim Al Khayari

If there is another Global Administrator, please ask them to follow the instructions in this article to reset your MFA authentication methods so that you can register your authentication methods again: Manage authentication methods for Microsoft Entra multifactor authentication - Microsoft Entra ID |….

If you are the sole Global Administrator and you are unable to reach the appropriate support team by phone, you can also consider submitting a support request directly as an alternative option:

-Create a temporary Microsoft 365 tenant using a trial license: Go to Microsoft 365 Business Plans and Pricing and click Try for free to set up a temporary Microsoft 365 tenant with a trial license.

-Use this new account to sign in to the Microsoft 365 Admin Center and submit a support request on behalf of the affected tenant.

-Select the Help & support (headset) icon >If Support Assistant is enabled, turn it off >Type contact support in the search box >Select Contact support, then choose Phone or Email to submit your request.

Note: This method doesn't require you to use your new account for your business. Instead, it allows you to create a temporary global administrator account so you can submit a support request, as your original global administrator account is locked out due to issues with multi-factor authentication. The trial account is free for one month. Be sure to delete it after submitting your support request to avoid any automatic renewals or charges from Microsoft.

For further instructions, you can refer to the following Microsoft guides:

Get support - Microsoft 365 admin | Microsoft Learn.

Cancel your Microsoft business subscription in the Microsoft 365 admin center | Microsoft Learn

I hope this information helps.

Please note that this is a user-to-user support forum, and I am not a Microsoft Support representative. I can share my understanding based on the information publicly available, but I do not have access to Microsoft’s internal support systems or the ability to escalate cases directly to the appropriate Microsoft Support team.