change domain name

Occasional Visitor


my company wants to change domain name for Office 365

actually the user name is:


 and we would like to change in :



The new user name will be the same with Outlook email address:


Anyone could tell me the steps to solve this problem.


Thank you

1 Reply
First off you need to add your domain to office 365! Basically this is done by following the steps in below link:

After adding the domain all the required dns records needs to be altered to point to Office 365! There is guidance in the link as well!

When the domain is added you can now change the username (UPN) and primary mail for the users to your custom domain!

If this is a cloud only users ( not synced from AD ) you can change this in the admin portal -> users or via powershell

If it’s synced make sure to add the UPN (your domain) in your AD and add it as a UPN on your users! Next sync it will change the UPN in office 365