Cannot Verify Identity for Azure Login – Error 399287

Anonymous
2025-06-11T06:12:27.67+00:00

When I select phone verification for a tenant directory, I am prompted to verify my identity via SMS.

Clicking it immediately fails and spits out the following error code.

Error details:

  • Service: Microsoft Azure
  • Error Code: 399287
  • Request Id: 2f4ab37a-e9cf-470f-93c5-778afdf64f00
  • Correlation Id: 8b95d636-a665-4697-bee1-3054a5e8bac7
  • Timestamp: 2025-06-11T05:59:13Z

The verification method is SMS via phone number from someone at our company.
It should still be OK to use, Azure's just seemingly not willing to use it at all.

https://learn.microsoft.com/en-us/answers/questions/2200691/unable-to-verify-identity-for-azure-login-error-39

The only previous thread I saw mentioned a resolution with engineering.
I'd be grateful for any help - this is an issue with a client that we've tried to bring up with support.

Microsoft Security | Microsoft Entra | Microsoft Entra ID

2 answers

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  1. Wildford Chiwana 0 Reputation points
    2025-10-20T14:55:48.4566667+00:00

    Hi Ogbebor, I have the same situation but unfortunately the admin account is the one who is locked by MFA. What can i do to recover ou change?

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  2. Akpesiri Ogbebor 3,120 Reputation points Volunteer Moderator
    2025-06-11T09:49:26.68+00:00

    Hello Ethan

    Thanks for contacting MS Q&A. I will be able to help you with resolving your issues.

    Error code 399287 in Azure AD means that the phone number you’re trying to use for SMS-based MFA has been blocked by Azure’s PhoneReputation service (sometimes reported as “multi-factor authentication method is blocked”) because it was flagged with a poor reputation.

    Docs - https://learn.microsoft.com/en-us/answers/questions/2200691/unable-to-verify-identity-for-azure-login-error-39

    How to resolve it.

    Open an Azure support request

    • In the Azure portal, go to Help + support → New support request

    • Problem type: “Identity” → “Multifactor Authentication”

    • Problem subtype: “MFA method blocked / Phone reputation”

    • In the Details section, include:

    • Tenant ID
    • Phone number
    • error code, request id, correlation it and timestamp of the failure • Submit the ticket and escalate to the Engineering (PG) team if possible.

    Microsoft staff in community threads have repeatedly pointed users’ cases to the PG team for a backend unblock; once unblocked, SMS MFA will work again.

    Docs - https://learn.microsoft.com/en-us/answers/questions/2247018/issue-with-sms-authentication-(error-code-399287)

    If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

    Siri

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