Anyone who has access to your account, regardless of permission level, uses a seat. Administrators through Contractors all cost the same if they have access to the tool as Licensed Users. Licensed Users are those who have logins to the tool and can track time (actuals) or view the plan. Admins and Project Managers can also track time for people, so long as those people are active in your account.
If you want to reduce the number of seats in your account, you need to archive people so they no longer have access. Once they’ve been archived, you can unarchive those people without re-inviting them so they will no longer be able to login but you can use their profile for resourcing purposes.
Note: When you archive a person, it removes their future assignments from the Schedule. Those assignments remain on project pages, in case you need to reassign the work. If you want to revoke a person's access without losing their schedule, please send us their first and last name and we will adjust on the back end.