Abstract: A billing system for a telecommunications network uses a monitoring software agent to monitor messages, indicative of individual calls on the network, passing between a service switching point and a service control point. Call record information is extracted and is stored in a local call record database. Information from each call record database is then passed on to a central database, using updating mobile agents, the central database being accessible to such agents and report building agents which can extract billing information as requested by an operator. By monitoring the messages as they pass, the system can provide real time billing information without needing to poll the switch at the service switching point.