Need to change an Office 365 user’s primary email address? We’ll show you how.

If you want to change an Office 365 user’s primary email address when it’s synchronised with on premise Active Directory, you’ll need to have administrator access to PowerShell. You’ll also possibly need to enable signed scripts to be run in Powershell, if you haven’t already done so using the following command in an elevated PowerShell session:

Set-ExecutionPolicy RemoteSigned

With these two requirements in place, you should run through the following steps.

1. Firstly you’ll need to connect to your Office 365 tenant’s Exchange Online PowerShell.
Run the following commands

Install-Module ExchangeOnlineManagement

Connect-ExchangeOnline

2. You’ll need to type in your Office 365 tenant admin credentials in the login box.

3. Now you’ll be able to run the command that’ll set the primary mailbox address

Set-Mailbox *username* -WindowsEmailAddress user@domain.com

Change *username* to the login ID of the user that is within AD and also replace user@domain.com to what you want the email address to be.