A WAP Charging Gateway, and a method and system, for arranging transaction-based billing for WAP services in a telecommunication system that includes a telecommunication network, a terminal device connected to the telecommunication network and used for accessing WAP services, a WAP Gateway connected to the telecommunication network, a content provider of WAP services connected to the WAP Gateway, a billing log file, a transaction manager for recording transactions associated with billable services and generated from different WAP protocol levels in the billing log file, and reading devices for reading the billing log file. Transactions associated with billable services, generated from different WAP protocol levels, are written to the billing log file and are read from the billing log file (LOG). The transactions in the billing log file are converted into a readable form. First rules are applied to the converted transactions to generate and store predefined transaction parameters, and second rules are then applied to the stored transaction parameters for generating chargeable transactions therefrom.