Abstract: A system by which external users, such as subscribers and service providers, can update their service data is disclosed. The system permits users to update their service data in a secure and controlled manner on a self-service basis in an intelligent network or other telecommunications network. An access system separate from the actual telecommunications services managing network elements is implemented in the invention, the access system providing the customers and service providers with an open interface to these network elements through a public data network. The access system controls access to the actual network elements by, for example, authenticating the party requesting access, checking whether the requesting party is associated with the data he/she desires to manipulate, and/or checking to which processing operations the requesting party is entitled. The users can thus access their own service data in the network elements managing the data in a manner controlled by the access system.