Hi ​@JA09336, welcome to the Box Community!

You cannot directly “disable” the unmanaged users as they are unlicensed personal accounts outside your enterprise control. However, you can manage and mitigate risks related to unmanaged users such as converting them to managed users, delete unmanaged users, remove collaboration access, and use domain auto enrollment to prevent unmanaged user creation.

You may consider the auto enrollment which is a feature that:

• Prevents users from creating free Box accounts using their company email
• Ensures that new users with the company email domain who have been invited to collaborate on managed content are enrolled as managed users of the enterprise

Enable this option on verified domains to prevent managed content from being accessed from free accounts, especially after employees leave the company.

Auto enrollment for a domain means that potential users who attempt to create a Box account using an email address in a domain you manage will be required to enroll as a managed user with that email address. This will result in:

• Your paid seat count incrementing.
• The user will be subject to all of your account security requirements, including SSO.

For instructions, check out: Enabling Auto Enrollment for a Managed Domain

Please let us know if you need further assistance.