Within the Account Management section, go to the ManageSub-Accounts page. Select the appropriate Sub-Account and click "Manage Client Administrators." Choose the Client Administrator you want to add from the drop-down menu and "Apply Changes."
To add a new Client Administrator enter their details in the fields provided. You can then select them from the drop-down menu to add them to the Sub-Account and "Apply Changes."
NOTE: If an added user was not already a Client Administrator or User, they will receive a Welcome Email when you apply the changes.