Can't login my number changed

If this is a work or school account, and the verification code is going to an old phone number, use one of these paths:

1. If another sign-in method is available, sign in to the Security info page and select Update info. Then use a method that still works, or choose I don't have any of these to replace the security info.
2. If no method works and MFA is blocking sign-in, contact the organization's IT admin. An admin can reset the MFA settings and require the account to provide contact methods again.

Admin reset steps:

1. Sign in to the cloud service portal as an admin.
2. Go to https://account.activedirectory.windowsazure.com/usermanagement/multifactorverification.aspx.
3. Select the affected admin account.
4. Select Manage user settings.
5. Select Require selected users to provide contact methods again and save.

If this is a personal Microsoft account, when prompted for verification select I don't have any of these and follow the prompts to update or add new security info. If verification codes are not arriving, avoid repeated requests because that can temporarily block code delivery. Also check junk mail for messages from @accountprotection.microsoft.com, and if SMS is used, make sure the phone is not blocking unknown numbers.

If sign-in still fails, use the Sign-in Helper.

Important: do not change all security info at the same time, because the account may be restricted for 30 days.

References:

• Common problems with two-step verification for a work or school account
• Can't use Azure Multi-Factor Authentication to sign in to cloud services after you lose your phone or the phone number changes
• Troubleshoot Microsoft verification code issues
• I can't sign in to my Microsoft account
• Microsoft account security info & verification codes