Subject: Issues logging in – Error code 399287

Question

I am trying to log into my email account but I keep receiving error code 399287.

I am using the same phone number I have always had. From what I can gather, it seems like my number has been blocked. I have not used my phone number for any inappropriate activities, so I don't understand why this is happening.

What steps should I take to resolve this issue and regain access to my account?

Error Code: 399287

Request Id: 24ebabea-f096-41d8-b03b-a799878d4300

Correlation Id: c0510cc2-a081-4b13-bc7a-9588b2db9184

Timestamp: 2026-04-27T12:11:03Z

Answer 1

Error code 399287 indicates that the phone number being used for SMS verification has been blocked for having a “bad reputation,” so verification codes will not be delivered and sign-in cannot complete using that number.

To move forward and regain access, use these steps:

1. Avoid repeated verification attempts
   • Do not keep retrying SMS verification, as excessive or repetitive requests can cause or extend blocks on verification methods and codes.
2. Try an alternate verification method (if available)
   • On the sign-in screen, choose I don’t have a code or Use a different verification option and:
     • Use an alternate email address or backup phone number previously added as security info.
     • If verification codes are sent by email, confirm that the email is a primary alias or a configured verification email and check the junk folder for messages from @accountprotection.microsoft.com.
3. Check for other issues with verification codes
   • Make sure the phone is not blocking texts from unknown numbers.
   • Confirm the number on the account is a mobile number (not VOIP) and is entered correctly.
   • If SMS is delayed or not arriving due to regional or service issues, wait and try again later instead of repeatedly requesting new codes.
4. Wait out temporary blocks
   • If the number or account has been temporarily blocked due to unusual activity, high volume of requests, or compromised traffic from the region, the block may clear automatically after some time.
   • Wait at least 24 hours without repeated attempts; if still blocked, wait longer (up to about a week) before trying again.
5. Use the sign-in helper
   • Run the Microsoft sign-in helper tool to diagnose the sign-in problem and see available recovery options for the account.
6. If still unable to receive codes or sign in
   • If no verification method works or the phone number remains blocked, use the available account recovery options (such as alternate email) and, if needed, contact Microsoft Support through the official support channel for additional guidance.
   • Note that support agents cannot send verification codes, password reset links, or directly change account security details; recovery must still go through the automated security and verification process.

These steps align with how Microsoft handles blocked verification methods and delivery issues for verification codes and are the supported paths to restore access.

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References:

• Troubleshoot Microsoft verification code issues
• Error Code: 399287 - Microsoft Q&A Unable to Verify Identity for Azure Login – Error 399287
• Azure has blocked myphone number for SMS verification due to a “bad reputation” flag - Microsoft Q&A