Accounting system in a network

A coupled data network with an accounting system is disclosed. The coupled data network includes a foreign network and a home network. The foreign network includes a base station with an access hub and a foreign mobile switching center with a serving registration server, the access hub including a serving inter-working function, the serving inter-working function including a foreign accounting collection module. The home network includes a home mobile switching center with a home inter-working function, the home inter-working function including a home accounting collection module. An end system is a subscriber to the wireless data network and coupleable to the foreign access hub. The home and serving accounting collection modules collect accounting data on message traffic transported between the end system and a communications server through the home inter-working function and through the serving inter-working function.