Charging for roaming users in ims networks

Communication networks and methods are disclosed for sharing charging information between a home IMS network and a visited IMS network. If a signaling message for a session is received in the visited IMS network, the visited IMS network assigns a visited charging identifier (e.g., ICID), and shares the visited charging identifier with the home IMS network through signaling messages. Similarly, the home IMS network assigns a home charging identifier, and shares the home charging identifier with the visited IMS network through signaling messages. When CDRs are generated in the home IMS network and the visited IMS network, the networks include the home charging identifier and the visited charging identifier in the CDRs so that billing systems may more easily correlate the CDRs from the different IMS networks.