Below are possible actions you can use to manage sub-accounts.

AddSubUser Add a new sub-user.
AddTrialUser Add a new trial sub-user.
UpdateSubUser Update existing account information for a sub-user.
DeleteSubUser Delete a specified sub-user.
GetUserInfo Return account information about a specific sub-user.
GetSubUsers Returns a list of all active sub users and their account info.
GetASM Returns the average system metric information of selected user.
GetStorageSpace Returns storage utilization for specific user.
GetBandwidthStat Returns encoding bandwidth for specific user.
GetBandwidthStatGroupDate Return encoding bandwidth for specific user by date.