Licenses in use are tracked over a rolling 30 day period.  As users login each login is tracked and date stamped.  User licenses in use can be viewed under Settings --> License on the Server Admin Panel.

For example:  On a 20 user license if 15 unique users login over a rolling 30 day period the licenses displayed will show 15 used/20 available.

Note - the number or user licenses used will display only after day 1 of the initial install or upgrade.  Manually editing the user login licensing file is a violation of the license agreement and will render the licenses used calculation as invalid.

Trial licenses and subscriptions expire in 30 days.  After 30 days, if not renewed or subscribed, MyWorkDrive functionality will be reduced to 2 users and 200 KB file transfers and other reduced functionalities until a permanent license or subscription is active.