I got locked on MFA step while trying to login to my Microsoft Account of Developer Program

John Salchichon 0 Reputation points
2026-07-20T18:46:54.3433333+00:00

I am the owner/administrator of a Microsoft 365 Developer Program tenant. MFA verification by SMS fails with Error 399287 and I have no alternative authentication method available. I need the case reviewed by the Data Protection Team to regain access.

User:[Moderator note: personal info removed]

Tenant: [Moderator note: personal info removed]

Error Code: 399287

Request ID: [Moderator note: personal info removed]

Correlation ID: [Moderator note: personal info removed]

Timestamp: 2026-07-20T18:08:35Z

I am locked out by MFA and cannot access the Developer Program tenant

Microsoft 365 and Office | Development | Other

2 answers

Sort by: Most helpful
  1. Michelle-N 20,645 Reputation points Microsoft External Staff Moderator
    2026-07-21T10:04:24.3266667+00:00

    Please note that Q&A forum is a public platform, and moderators will modify the question to hide personal information in the description. Kindly ensure that you hide any personal or organizational information the next time you post an error or other details to protect personal data.

    Hi @John Salchichon

    In this situation, there are two official paths you can take to regain access to the tenant:

    1.Please visit the following page and reach out to phone number via: Customer service phone numbers - Microsoft Support

    From what I know, you will need to get past the initial AI system to reach the live support team. You can refer to the guide below for tips on how to get through more easily:User's image

    2.If method 1 is not working, please follow this link to create a trial tenant: https://www.microsoft.com/en-us/microsoft-365/business/microsoft-365-business-basic?msockid=3eb6980b5c6860e63a588d0c5d1761d6 - after that you will be able to access to Microsoft 365 Admin Center to raise the ticket

    Assuming that you have already created an account after registering a free trial and you can go to Microsoft 365 admin center and click "Help & support" icon to raise your ticket. The agent will be able to create a ticket for you under the affected tenant and then transfer this ticket to Data Protection team who could help you to regain access.     

    User's image User's image

    Please mention that you are raising ticket on behalf of the affected tenant that you do not have access to. The support team will help you to create ticket on the affected tenant then later on the Microsoft Data Protection team will assist you.

    Note: This process will take more time than usual (7-14 working days) for your account to get access again as Data Protection is always overwhelmed with the number of tickets. As I am forum moderator, I do not have access to Microsoft internal system to assist or push this process to be quicker.

    On the other hand, if you do create the trial and it resolves the issue, please remember to cancel the subscription afterward to avoid any related charges. 

    I hope my information is helpful. Please give me any updates once you get this resolved.


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

    Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

    Was this answer helpful?

    0 comments No comments

  2. John Salchichon 0 Reputation points
    2026-07-20T18:49:46.4166667+00:00
    1. Account: [Moderator note: personal info removed]
    2. Error message: "Sorry, we're having trouble verifying your account. Please try again."
    3. Error Code: 399287 (the screenshot appears to show 399287, not 339287)
    4. The only available MFA method is Call or text to a phone ending in 10.
    5. Timestamp: 2026-07-20T18:08:35Z

    Was this answer helpful?

    0 comments No comments

Your answer

Answers can be marked as 'Accepted' by the question author and 'Recommended' by moderators, which helps users know the answer solved the author's problem.