There is provided a method of operating a hearing device (10, 11) to be worn by a user, comprising: defining a plurality of hearing device services and assigning to each hearing device service a service access confirmation level selected from a plurality of hierarchically structured service access confirmation levels; providing an access software platform for enabling third party service access to the hearing device services; providing at least one application program adapted to provide a third party service to the hearing device, each application program adapted to utilize the access software platform and at least one of the hearing device services; providing a manufacturer access service for approving or denying access to the hearing device for each of the application programs depending on whether or not approval for the respective service access confirmation level(s) has been previously obtained.