A method for billing a subscriber to a cellular telephone service for a VoIP call made by the subscriber, the method including determining when a subscriber to a cellular telephone service places a telephone call to a remote device using a local device associated with the subscription, where the telephone call has at least one VoIP call leg, capturing session information related to the telephone call, including information identifying the subscriber, and providing the information to a provider of the cellular telephone service, thereby enabling the cellular telephone service provider to bill the subscriber for the VoIP call.