If you have previously sent an invite and the user never accepted their invitation to join your account, you can delete this user and re-gain your license by following the steps below:
Step 1: Navigate to your Team page.
Step 2: Select the "Users" tab.
Step 3: Find the user you want to delete.
You'll see the date that your invite was sent.
Step 4: Navigate to the 3 dots on the right side of the user.
Step 5: Click "Delete" from the dropdown menu.
Step 6: Confirm that you want to delete the user.
They will now be removed from your users list and you can either invite them again or bring in a new user.