The subscription for RealmJoin is user-based.

User definition

The subscription of a "user" is required for each Intune subscription, that is assigned to a user in the Microsoft 365 tenant in scope for the RealmJoin instance.
The minimum amount of users that can be subscribed for one organization is 1.000.
RealmJoin does not display your license consumption. Please ensure compliance with the licensing terms by monitoring the Intune subscriptions in your tenant on a regular basis.

Device limits per user

One single user may be assigned to up to 10 devices.

Subscription scope

A RealmJoin subscription may be used for the clients and users of one organization.
It is not allowed to
  • Use one RealmJoin subscription for multiple organizations
  • Split one RealmJoin subscription and/or re-sell it to multiple organizations