Purchasing more licenses
If you need to add more users to the account but you don't have any more licenses, you can purchase more from Account>Subscription.
You'll receive an instant charge that will cover the new users until the end of the month, then the monthly subscription will be updated to the new license count.
Downgrading to fewer licenses
If you realize that you need fewer users and you want to change the licenses, you can edit the subscription from the Subscription page.
No refund will be made for unused licenses.