You can manage sub-accounts within your organization. Here are the steps:
To activate a sub-account:
Select the sub-account you want to activate (Check box on the left)
Find the 3 dots (next to "Add Account")
Click on "Grant Access"
To de-activate a sub-account:
Select the sub-account you want to activate (Check box on the left)
Find the 3 dots (next to "Add Account")
Click on "Revoke Access"
To manage the account:
Find the 3 dots next to the sub-account you want to manage
Click on "settings"
You can change the limit of the number of admins and learners under this sub-account