Microsoft 365 admin center - Unable to login by verifying using SMS

Question

Microsoft 365 admin center - Unable to login by verifying using SMS

Phill Hayman 210

Good morning!

We're unable to log into our Microsoft 365 tenant's Admin Center because verifying using SMS is not working. The system claims the account is not verified but doesn't allow any other options (error Code 399287).

I found in a few other post this can be solved by the engineering team, so I'm tagging the person from Microsoft that was able to get this fixed: @Raja Pothuraju , could you do the same for me?

Kind regards,

[Moderator's note: PII removed]

Moderator's note: Moved from Microsoft Security | Microsoft Entra | Microsoft Entra ID

Shubham Sharma 17,940 Reputation points Microsoft External Staff Moderator

2026-05-25T01:09:21.4533333+00:00

Phill Hayman

Welcome to Microsoft Q&A Platform.

I understand you're experiencing issues logging into your Azure account due to MFA. Based on error code 399287, it appears your multi-factor authentication method is blocked because the phone number has a bad reputation.

Could you please send your requested details via private message so we can further assist?

Thanks

Answer accepted by question author

Shubham Sharma 17,940 Microsoft External Staff Moderator

Phill Hayman

Thank you for sharing your details via private message.

I’ve reached out to the engineering team regarding the MFA issue on your account. They have now unblocked it from the backend and cleared the bad reputation associated with it. You should be able to log in to the Azure Portal without any issues.

Please try signing in and verify if you can complete SMS authentication successfully. Let me know if you encounter any problems.

As a best practice, I recommend registering the Microsoft Authenticator method for your account instead of relying on SMS. SMS and voice call authentication methods are more vulnerable to IRSF attacks (telephony fraud) and are generally less secure.

For better practice, I recommend registering with Microsoft Authenticator method to your account instead of SMS method as these SMS/Voice telecom auth methods are susceptible to IRSF attacks telephony fraud.

If the resolution was helpful, please take a moment to accept the answer and upvote it 👍 to make it helpful to the community.

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Shubham Sharma 17,940 Reputation points Microsoft External Staff Moderator

2026-05-25T01:09:21.4533333+00:00

Phill Hayman

Welcome to Microsoft Q&A Platform.

I understand you're experiencing issues logging into your Azure account due to MFA. Based on error code 399287, it appears your multi-factor authentication method is blocked because the phone number has a bad reputation.

Could you please send your requested details via private message so we can further assist?

Thanks

Answer 1

Dear @Phill Hayman,

Please note that none of moderators could help you with this while your account are belonged to an organization to do this action. Kindly follow these steps:

Option 1: You may need to contact the Data Protection Team at the service phone number via this link: Customer service phone numbers - Microsoft Support.

The main objective is to go through the IVR (automated system) until you reach a live agent and emphasize this very important security factor. Please help me try this script below, this is a commonly used script for authentication issues to bypass IVR, but you can try to see if it helps get through the system. Please help me to speak loudly, only keywords, clearly and patiently waiting for the machine's response. First, when you call the hotline, they will ask you what kind of problem you are facing with.

Answer: Authenticator.
A: What products do you use?
B: Office 365 for business.
Verification: Education or corporate account?
B: For companies
A: Are you an administrator?
B: Yes.
A: Are there other administrators in your organization?
B: No.
A: I need one.... Service request?
B: Yes

During the call, you must provide information related to the subscription, such as your company name, billing history, phone number, and alternate email address. This information helps data protection teams verify identities and securely regain access to administrator accounts.

Option 2: Create a new tenant with trial subscription to access and submit a ticket in the Admin Center.

If you still can't get in touch with a real person for help, help me try the following:

Sign up for a free trial (new tenant with trial subscription) of Microsoft 365 at this link: Compare All Microsoft 365 Plans | Microsoft. The goal is to create a temporary tenant with a Global Administrator account so that you can sign in to the Microsoft Admin Center. Once connected, you can submit a support ticket directly to Microsoft. Please remember to cancel the trial subscription once your issue is resolved to avoid unwanted charges.

How to submit support ticket in Admin Center: Get support - Microsoft 365 Admin | Microsoft Learn

Once you contact the Data Protection team, you will be required to provide proof of ownership of the company. This allows them to verify their identity and help reassign the Global Administrator account.

As a moderator, I do not have the tools to investigate your specific account directly, as this is a support forum between users. Moderators and collaborators, including external Microsoft employees, may not directly intervene in the functionality of Microsoft products or access internal systems. Our role is limited to providing technical guidance on reported problems, requests, or ideas. However, I will do my best to guide you as clearly as possible.

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