This user is synchronized with your local Active Directory. Some details can be edited only through your local Active Directory.

Yuck, but how do we change it from Active Directory. Bah, nevermind that, lets just change it directly on O365 from a powershell!

  1. First you need the Sign-in assistant and the Azure AD module
  2. Fire up power shell and run
  3. Put in your O365 credentials and hit OK
  4. Then run this magical command where “[email protected]and[email protected]are the old and new usernames
    Set-MsolUserPrincipalName -UserPrincipalName [email protected] -NewUserPrincipalName [email protected]


Thanks to this post for the solution