How to Add UPN Suffixes in Active Directory

The User Principal Name (UPN) suffix is part of the logon name in Active Direcoty and when you create a new account, by default it will use the DNS name for your AD domain.

For example, your local domain name is "" then, your user will have a logon name like

In given times, you will have the need to add a new UPNs in your forest domain, for example, you are deploying a new Exchange server, and you would like to assign to your users the email domain, which in our example would be

What do you need to do to have the possibility to choose which UPN will be?

Setting up

1º - Log in to Windows Server with a domain administrator account.

2º - Open Server Manager using the icon on the desktop taskbar, or from the Start screen.

3º - Select Active Directory Domains and Trusts from the Tools menu.

4º - In the Active Directory Domains and Trusts management console, right-click Active Directory Domains and Trusts in the left pane and select Properties from the menu.

5º - In the dialog box on the UPN Suffixes tab, type the name of the suffix that you would like to add to your AD forest in the Alternate UPN suffixes box. Click Add and then OK.

In the end, you will have set a new UPN to your Forest Domain and now, you can choose which UPN you want to use: