Communication networks and methods are disclosed for performing online charging credit control in a visited network when a user is roaming. The visited network which is providing service to a roaming user includes a proxy online charging system (OCS) that communicates with a home OCS in a home network of the user. The proxy OCS transmits an online charging request message to a home OCS in a home network for the roaming user requesting charging information for the roaming user. The proxy OCS receives an online charging response message from the home OCS that includes the charging information for the roaming user. The proxy OCS then processes the charging information to perform credit control for one or more network elements in the visited network that is serving the session.