Office 365 2FA
If you have two factor authentication setup on your Microsoft 365 account, here is how you change the phone number that is called or the method of authentication used.
Login to Microsoft 365
Follow the step below to change the number. The location of where 2FA is setup is somewhat buried.
- Sign in to https://myapps.microsoft.com
- Select your account name in the top right, then select profile or view account.
- Select Additional security verification or Security info.
- You will see the page below.
From this page there are various things that can be done, including the number that is called for your second factor of authentication. You can also change the default method of authentication for the second factor or add another method.
Also note that the link on the bottom
If you loose a device then you can logout all devices that are currently logged into your account.