As a Great Teaching Coordinator or Assistant Coordinator, you can quickly view how many licences your school or college has available as part of your subscription. Simply head to the “School management" page of your account and click on the orange "Manage teachers" button. 
Beneath your registration link, you'll find the maximum number of licences you have available to you. Scroll down to the bottom of your list of teachers and this will tell you how many registered users you currently have on the GTT. 
As a Great Teaching Coordinator or Assistant Coordinator, you are able to deactivate users in your organisation, and then you can re-use that licence. Find out more about how to do this here.
If you have used all of your licences and think you might need a few more before your subscription renews, please contact us at advisors@evidencebased.education and we'll be happy to help.