Method for billing a service in a Telecommunications /data network

A method for charging a service in a telecommunications / data network, in particular UMTS mobile network, wherein billing-relevant operations on network elements that implement a charging interface are transmitted by means of an adapted transmission protocol to a charging system, as a transmission protocol, a hot-billing protocol is used supporting a termination message of the debiting system, wherein a network element involved in the debiting process sends a message to the debiting system at the beginning and at the end of the service, and the service is timed in the debiting system and a debit is made in response to the measurement result in parallel with the service execution.