Urgent: Admin Account Locked Out due to Error 399287 (MFA SMS Blocked)

Hi Queith,

Thank you for reaching out and for providing the details of your situation. I have received your request regarding your Global Administrator account, which is currently locked because the MFA verification SMS is blocked with Error Code 39928. This error occurs because the Microsoft Entra telephony fraud protection system has temporarily flagged your phone number, and as a result, SMS and voice verification codes cannot be delivered to it.

I’m truly sorry to hear that you’re currently unable to sign in. If your account is also an admin account and there are no other available global administrators in your tenant, then the only way to regain access is to contact Microsoft support. Please try locating the appropriate hotline for your region here: Customer service phone numbers - Microsoft Support 

In this situation, the Microsoft Data Protection team has tools and processes in place to verify identity and regain access to administrator accounts. 

Here are some tips and an example of a prompt to help you navigate the IVR more effectively: 

(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.)   

In some regions, the initial interaction may be automated, so here’s a general idea of how the conversation might go to help you prepare:     

• What kind of problem are you experiencing?        
• Answer: Authenticator        
• What products do you use?        
• Answer: Office 365 for Business        
• Is this for an education or company account?        
• Answer: For companies        
• Are you an administrator?        
• Answer: Yes        
• Are there any other administrators in your organization?        
• Answer: No. I am the only admin in my tenant         
• Do you need a... Service request?         
• Answer: Yes. I need to create a ticket. Please send me directly to the Data Protection Team.     

During the phone call, you will need to provide the information associated with your subscription, such as your company name, billing details, phone number, and an alternate email address, etc. This information allows the Data Protection team to verify your identity and securely assist you in regaining access to your administrator account.     

I also recommend calling during business hours. In my experience, it can be difficult to get through to the correct support queue, and automated systems don't always work as expected. If you can't get through on your first try, I suggest trying again later or at a different time.

In case you are unable to contact the frontline support:

• Consider signing up for a trial subscription to create a new tenant via Microsoft 365 Business Plans and Pricing | Microsoft 365

• Once set up, you can access the new tenant's admin console and submit a support ticket to speak with the data protection team on behalf of the previous tenant.
• Once your issue is resolved, please remember to cancel the trial subscription to avoid any unintended charges.

If your organization's subscription is from a partner or reseller: Contact the reseller's support provider to help open a service request on your behalf instead.

I hope these steps help you create a support ticket successfully and move closer to regaining access to your administrator account. While I’m not able to intervene directly, guiding you to the right support team is the most effective help I can provide here. 

Hope you're able to get this resolved soon.

Best regards,