How can I delete my old phone from my Microsoft account?

To remove the old phone and fix the two-step verification issue, update the security verification methods on the Additional security verification / Security info page.

Follow these steps:

1. In a browser, go to the Additional security verification page: https://account.activedirectory.windowsazure.com/proofup.aspx?proofup=1 (or open office.com, sign in, select your account picture → View account → Update info to open the Security info page).
2. On the Security info page, locate the entry for your old phone under the list of methods (for example, “Phone” or an old number).
3. Select Delete next to that old phone entry.
   • If prompted to confirm, choose Delete again.
4. After removing the old phone, select Add sign-in method.
5. Choose Phone as the method, then add your current phone number and complete the verification.
6. If using the Microsoft Authenticator app on your new phone, also:
   • Remove any outdated phone/Auth app entries as above.
   • Re-add the method and follow the prompts to set up the Microsoft Authenticator app on the correct device.

Once the old phone is removed and the new phone/Auth app is added, the two-step verification codes should match and sign-in should complete successfully.

References:

• Use a screen reader to set up and troubleshoot multifactor authentication