2FA not working

To change the phone number used for Microsoft 2FA, update the security info on the account. The exact steps depend on whether this is a personal Microsoft account or a work/school (Microsoft 365/Entra ID) account.

Personal Microsoft account (Outlook/Hotmail/Live)

1. Go to the Microsoft account security page and sign in: https://account.microsoft.com.
2. Select Security and then Security info.
3. Under your current phone number, select Remove if you no longer use it.
4. Select Add sign-in method (or Add security info).
5. Choose Phone as the method.
6. Enter the new mobile number and complete the verification (SMS or call).

If you no longer have access to any of the listed phone/email methods when signing in:

1. On the verification screen, select I don't have any of these.
2. Follow the prompts to add new security info (new phone or email) and regain access.

Work or school account (Microsoft 365 / Entra ID)

If this is a work or school account using MFA:

If you can still sign in with another method (e.g., Authenticator app or backup email):

1. In a browser, go to the Additional security verification page: https://account.activedirectory.windowsazure.com/proofup.aspx?proofup=1.
2. Delete the old phone number:
   • Find Security info type: phone and choose Delete phone, then confirm.
3. Select Add sign-in method.
4. Choose Phone as the authentication method.
5. Enter the new mobile number and complete verification.

If you cannot sign in at all because MFA is blocking you and there is no working method:

• Contact a global/cloud admin in the organization and ask them to reset your MFA settings:
  1. They sign in to the cloud service portal as admin.
  2. Go to https://account.activedirectory.windowsazure.com/usermanagement/multifactorverification.aspx.
  3. Select your user account.
  4. Choose Manage user settings.
  5. Check Require selected users to provide contact methods again and select Save.
• After this, sign in again and reconfigure MFA with the new phone number.

If you are the only admin for a business tenant and are completely locked out (no SMS, no Authenticator, no backup methods), a support case with Microsoft may be required to regain access.

References:

• Use a screen reader to set up and troubleshoot multifactor authentication
• Troubleshoot Microsoft verification code issues
• Can't use Azure Multi-Factor Authentication to sign in to cloud services after you lose your phone or the phone number changes
• Change the email address or phone number for your Microsoft account
• Authenticator locked and cannot access at all after replacing phone - Microsoft Q&A
• I need to reset my mfa methods - Microsoft Q&A
• I have a new phone number and I want to add it
• I have a new mobile phone and I want to add it to MFA