MS365 login not possible, account is not verified

Hello @WR,

Thank you for reaching out and sharing the error details.

To assist you better, I’d like to confirm a few points first: 

• Are you using a personal Microsoft account (such as Outlook.com or Hotmail) or a business/school account? 
• Before this issue occurred, did you reinstall or remove the Microsoft Authenticator app on your device at any point? 
• Could you confirm the type of subscription you have (for example, Microsoft 365 Business Standard, Microsoft 365 Personal, etc.)? 
• If possible, please share a screenshot of the error message you see when trying to log in. This will help us understand the situation more clearly. 

Please confirm these details and provide as much information as you can. The more context we have, the better we can guide you toward a solution. 

Looking forward to your update!

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Hello @WR

Thank you for sharing your screenshot.

Based on the error code you provided, Error 399287 means that Azure has blocked your phone number for SMS verification due to a “bad reputation” flag. 

To proceed, I’d like to confirm: 

• Do you still have your old laptop? If yes, can you log in successfully on that device? 

If you can still access your account from the old laptop, please log in to the Microsoft 365 Admin Center, reset your Multi-Factor Authentication (MFA) settings, and unblock the phone number. 

If you are the only admin in your organization:

Since you are the only admin, you will need assistance from Microsoft’s Data Protection team. This team has the authority and security procedures to verify your identity as the legitimate account owner and then reset your MFA settings from their end. Please try to find the related hotline number to call the frontline and let them raise a ticket for you: Customer service phone numbers - Microsoft Support    

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 direct to the Data Protection Teams.      

Once the issue is resolved, we strongly recommend using Microsoft Authenticator instead of SMS for future logins to avoid similar problems. 

If you encounter any difficulties reaching out to support via the hotline, please let me know so I can assist you further. 

Best regards,

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