Update Users to use Custom Domain

Any users created prior to adding the custom domain and setting it as the default will have a domain.onmicrosoft.com user principal name (UPN). While this works for signing in and receiving mail does not look great. The custom domain adds a more professional look and will be easier for anyone logging in or emailing users to work. Like most things there are multiple ways this can be achieved.

Microsoft 365 Admin Center:

1. Navigate to https://admin.microsoft.com.
2. Expand Users > Active users.
3. Select the desired user and click "Manage username and email".
4. Click the pencil next to the primary email address and username.
5. From the domains drop down, select your custom domain.
6. An alias for the domain.onmicrosoft.com domain is automatically created and you can also add additional aliases if desired.
7. If this is the account you are signed in with, you should be automatically logged off and need to reauthenticate.
8. Repeat the steps for any additional users. Any users created after the adding the custom domain can be created with the correct domain.

Entra ID Portal:

1. Navigate to https://entra.microsoft.com
2. Expand Users > All users.
3. Select the user you would like to edit.
4. Click the pencil for Edit Properties.
5. Under User principal name, change the domain dropdown.
6. Note this will not create an alias for the domain.onmicrsoft.com domain, if this is desired the contact information allows adding additional email addresses.

Azure Portal:

1. Navigate to https://portal.azure.com.
2. Search for Microsoft Entra ID if not already in the recent items.
3. Expand Manage > Users.
4. Select the desired user and click Edit properties.
5. Under User principal name, change the domain dropdown.
6. Note this will not create an alias for the domain.onmicrsoft.com domain, if this is desired the contact information allows adding additional email addresses.