A User Principal Name (UPN) is made of two parts, first is prefix that holds user account name and second part is suffix, that holds DNS name.

Example: user1@expertbrains.com

User1 is suffix and expertbrains.com is suffix.

If you want to change UPN then change the user’s username or set a different email alias as primary in the Microsoft Admin Centre.

You can also change UPN in the Azure AD admin centre by changing their username. You can also change UPN through PowerShell.

A user’s UPN (used for signing in) and email address can be different. If you want to create new email address for a user then add alias instead of changing UPN.

Types of UPN changes:

You can change UPN by changing prefix, suffix or both

  1. Changing prefix : If a person changes his name then you can update his account

User1@expertbrains.com to User2@expertbrains.com

  1. Changing the suffix: If a person changed divisions, you might get request to change his domain

User1@expertbrains.com to User2@expertbrainsgroup.com

OneDrive URL:

A user’s OneDrive url based on their UPN:

https://expertbrains-my.sharepoint.com/personal/user1_expertbrains_com

If you change the prefix to user2 and suffix to expertbrainsgroup.com , the user’s OneDrive url would change to

https://expertbrains-my.sharepoint.com/personal/user2_expertbrainsgroup_com

Sync

The OneDrive sync app on both windows and mac will automatically switch to sync with new OneDrive location after UPN change. While UPN change is propagating through your environment, you may find some error in the sync app that “One or more libraries could not be synced”. If you expand to see more information then you will get another message that “you don’t have permission to sync the library”. When you see this error then you should restart the sync app.

Error will disappear once the UPN change propagate completely and sync app is updated the user the user’s new OneDrive URL.

OneNote

After UPN change, you have to close and reopen the OneNote notebook stored in OneDrive.

Recent File:

Any links to the files including favourites, desktop shortcuts and recent lists in office apps and windows will no longer work. You have to brows and re-open active OneDrive files.

After UPN change you have sign out and sign in again in office client

Search and delve

After UPN change, it might take some time for files in new OneDrive url to be indexed During this time search results in OneDrive and SharePoint will user the old url. You can copy the url and update the portion for the new UPN.

Delve will also show old OneDrive for a time being and as activity happens in the new location, new links will start appearing.

SharePoint automated workflows and customization:

You have to update the OneDrive URL after changing UPN in case of using any customization.