
View federated-authentication user name conflicts in Apple Business Manager
In Apple Business Manager, you view federated-authentication user name conflicts in case you have to create new user name information for specific users. After a domain is successfully added, Apple reviews all existing Apple IDs by searching for any using that specific domain name. If an Apple ID is found to be using the domain name, Apple Business Manager lets you send a mail message—and a notification to any device connected to their iCloud account—to that person, letting them know they must update their Apple ID user name so that you can use it for your organization. During the update process, they don’t have to change their password and all their purchases and data remain in their account.
For example, say your organization registered the domain @acme.com several years ago and set up email addresses for all their employees. Jane Appleseed decided to use the email address she was assigned “janeappleseed@acme.com” as her personal Apple ID.
Even if Jane no longer works for the organization that registered acme.com, she still has the Apple ID with that domain name. Because you are setting up federated authentication for the domain name @acme.com, Jane must change her Apple ID user name so you can create the Managed Apple ID janeappleseed@acme.com if you want.

How Apple notifies users whose Apple ID conflicts
Apple will identify users whose Apple ID contains the domain name you’ve registered. Those users receive a mail message and a notification telling them they must rename their Apple ID. If they’ve not renamed their Apple ID yet, they keep receiving notifications and mail messages, with one final mail message at 60 days. After 60 days, the user’s Apple ID is automatically renamed to a temporary user name, and the original user name is released and claimed by your organization.
View federated-authentication user name conflicts
In Apple Business Manager
, sign in with an account that has the role of Administrator or People Manager.
Click Activity in the sidebar, then click Checking for Conflicts.
If any user name conflicts are found, you’ll see a dialog with the total number of user name conflicts.
WARNING: Be aware that enabling federated authentication will impact all users across the domain you federate. You should speak with your IT administrator before initiating the federation process.
Click Continue, click Send Notifications, then click OK.
A mail message—and a notification to any device connected to their iCloud account— are sent, letting each user with a user name conflict know they must change their personal Apple ID.
You can view the process of sending mail messages to users with a user name conflict in the Activity section of Apple Business Manager.