Microsoft Multi-Factor Authentication - Replacing your Phone or Mobile Device - Changing your phone number

Instructions to change your phone number used as a sign-in method (ensure you have the Authenticator app installed and working from your former/current device): 

1. Ensure you have the Microsoft Authenticator app and have used it to log in. 
    
2. From the My Sign-Ins page (easier when accessed through a computer):

• Using the working Microsoft Authenticator app from your former/current device, go to the My Sign-Ins page and and sign in. 
• Delete your existing Phone Authentication method.
• select + Add Method - Phone and follow the prompts to add the new phone number.  

You can check your authentication methods at any time from the Microsoft My Sign-Ins page.