Apple has introduced a new feature in Apple Business Manager (ABM) that allows administrators to control which Apple Accounts can sign in on managed devices. Apple calls this feature Apple Account on Organisation Devices. This setting is in your ABM tenant under Access Management-> Apple Services. Administrators can choose to allow either any Apple Account or restrict sign-in only to Managed Apple Accounts. This capability enables organizations to block users from utilizing Personal Apple Accounts on company-issued devices. Previously it was only possible to restrict on which device type Managed Apple Accounts can sign-in.