Neelix Consortium can have more than one billing entity and administrator. This is useful when more than one organisation, even separate division in one company, need to collaborate. Each billing entity will receive an invoice for users applicable users only.
Administrators (Maintenance Owner permission users) can manage users and choose which billing entity is sponsoring that user's subscription in the consortium.
We call billing entity as "Participant" in consortium settings.
Your account needs to have "Maintenance Owner" permission within the consortium to perform these changes. See more about user roles here.
To map a new Participant, you also need to be an Administrator of that participant / billing entity.