A method and apparatus for charging against prepaid credit in a communication network. When a first terminal requests establishment of a call to a second terminal, the network ascertains whether prepaid credit is involved. If so, accounting sessions are established between an accounting server and any accounting servers that will raise costs during the call. A session identifier is generated. Once the call is established, charging update data is sent from the accounting clients to the accounting server, where it is collated on the basis of the accounting session identifier, whereby enabling updating of the prepaid credit during the call.