Abstract: A telephone charging system prices calls made by customers in a telecommunications network. The system includes a local exchange which provides a call record for each call, a database containing details of the customers of the network, a database which contains the locations of the individual numbers, details of routes between the numbers and a set of tariffs for pricing calls, a processor which receives call records from the local exchange and data from the databases and uses the call records and data to price calls, and a store for storing details of the priced calls. In order to price a typical call, the processor evaluates a factor relating to the type of service used in the call, a factor relating to the type of customer, a factor relating to the locations of the calling and called number in the network and a factor relating to the day on which the call is made.