Patent ID: 7116968

Claim:
A method for charging an account related to a terminal device of a subscriber to a first data network for a network session rendered to said terminal device when roaming in a second data network, comprising the steps of registering said terminal device to said second data network, transmitting a network address of a first charging system related to said first data network from said first data network to said second data network, establishing said network session for said terminal device by said second data network, assessing in said second data network first charge information about said network session, transmitting said assessed charge information from said second data network to said network address of said first charging system, and calculating a charge for said network session at said first charging system using said incoming first charge information, wherein said step of transmitting said network address of said first charging system from said first data network to said second data network is performed before said step of registering said terminal device to said second data network.