Error 399287 BadReputation – Sole Global Administrator locked out of SMS MFA

Question

I am the sole Global Administrator of my Microsoft 365 / Microsoft Entra tenant.

My username and password are correct. SMS is the only MFA method registered on the account.

Microsoft is refusing to send the SMS verification code and returns:

Error Code: 399287 / BadReputation

There is no other Global Administrator and no alternative authentication method, so I cannot access the Entra Admin Center to reset MFA myself.

Please escalate this to the Microsoft Entra / PhoneReputation engineering team and clear the BadReputation block on my MFA phone number.

I can provide my phone number, tenant ID, username/email, country and country code via private message.

Error Code: 399287 Request ID: [Moderator note: Personally Identifiable Information removed] Correlation ID: [Moderator note: Personally Identifiable Information removed] Timestamp: 2026-08-15T09:27:10Z

Answer 1

I cannot use the phone route because the Lebanon IVR is Arabic-only for me and the calls are chargeable, and I cannot create a trial tenant because the payment setup is failing.

Could you please confirm whether you can open the Data Protection / Tenant Recovery support ticket on my behalf, as Microsoft Q&A moderators have done for other sole-Global-Administrator lockout cases?

I can provide my contact email, affected Global Admin account, tenant/domain, phone number, country, timezone, and any other required details privately.

Answer 2

disregard this

Answer 3

Dear @Leonid,

Good day! Welcome to Microsoft Q&A forum!

The 399287 error with “BadReputation” usually shows up when the phone number being used for verification has been flagged by Microsoft’s phone number reputation or risk‑based protection systems. When that happens, SMS-based MFA can get blocked or fail, even if the number itself is valid and working normally in other contexts.

Please note that this is a community forum where users help one another. I do not have control over user accounts, including login issues, password resets, or access changes. From my observations, it seems that issues are no longer being resolved via private message.

Therefore, if you are the only administrator in your organization, then you need to involve Microsoft Data Protection Team. Please try to find the related hotline number to call the frontline let them raise a ticket for you: Technical or Sales support phone numbers (for Work account, scroll down to find your region's number) 

In some countries, this is an automated conversation: First, when you call the hotline, they will ask you what kind of problem you are struggling with. 

Answer: Authenticator. 

A: What products do you use? 

B: Office 365 for business. 

Verification: Education or company account? 

B: For companies 

A: Are you an administrator? 

B: Yes. 

A: Are there any other administrators in your organization? 

B: No. 

A: I need one.... Service request? 

B: Yes 

(Important Note to reach a live support agent: Sometimes, you would hear the computer-generated voice at first, please kindly wait for it to end, and if an agent is available, you would be directed to them and get your support. Depending on your country or region, when you call the support number, you may hear an introduction of about 30 seconds such as "You can visit the link...". You can ignore this introduction and wait until you are presented with the options. Then press "1" as a business email user, and again "1" for technical help.) 

As an alternative, you can create a new tenant account and submit your request from there.    

To set up a new tenant, please follow these steps: 

• Visit Compare Office 365 Enterprise Pricing and Plans | Microsoft 365, choose any plan and click try for free to start a free trial.    
• Follow the guided setup process to create a new account for a new tenant. 

Once your tenant is created, you should be able to access the support portal and submit your ticket referencing your locked account without further issues.

In the ticket's description, you could refer to this message "Hello,

I am currently locked out of my Microsoft 365 tenant because multi-factor authentication is enforced, and I am unable to complete the verification process because of the error code 399287. I am the only global administrator for this tenant, which means I cannot access my account or the Microsoft 365 Admin Center.

To resolve this, I have created a new tenant and would like to be connected with the Data Protection Team to verify my identity and assist with regaining access. I am available to provide any required documentation or verification to support the recovery process."

Ticket Support: Log in the Microsoft 365 Admin Center using the newly created trial admin account (not the currently locked one) > Support > Help & Support. You can raise support ticket at: https://admin.microsoft.com/#/support/requests 

When you open a support ticket, make sure to turn off the Support Assistant (AI) in the Help pane.

A few customers have run into problems when the Support Assistant is on: sometimes the system doesn’t show the “Contact Support” option.

As you can see in the screenshot, just switch the Support Assistant to “Off” and then type in your issue. Once the AI is off, the “Contact Support” button will show up normally, and you can submit your ticket directly.

• After clicking on "Help & Support" button, you can type "I need agent support via phone or email". After that, you can click on "Contact support" 
• Choose contact method: "Phone" 
• Fill all the information in this contact support details, please describe your situation carefully so they will have enough information to help you. 
• Finally, click on "Contact me"
• After completing them, you will receive an email appointment for a meeting to review this issue professionally together. 
• For more details, you could refer to this article: Get support for Microsoft 365 for business 
• This new trial tenant will not give you access to any of the data or settings in your original locked tenant. It is solely a temporary means to contact Microsoft support.   
• Be prepared for Microsoft support to ask for verification of your identity and administrative rights for the locked tenant.   
• The resolution time might be longer as you are contacting support from a different tenant.   
• Remember to cancel the trial subscription for the new tenant once your issue with the original account is resolved to avoid any unintended charges. You can typically do this within the Microsoft 365 Admin Center under "Billing" > "Your products."      

Kindly let me know when there are updates or if you need further assistance. Any updates you’re able to share would be really helpful.

I'm here and happy to help! Thank you for your kindness and patience! 

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