Abstract: A system for providing alternative billing and service authorization for pre-paid wireless calls segments call flow to supporting subsystems and limits trunk usage exclusively to short pre- and post-call announcements. An Integrated Services Digital Network User Part (ISUP) Application, hosted by an SS7 Service Switching Point, keeps call state information, implements call-flow capabilities, and accesses resources for messaging. An Intelligent Peripheral (IP) provides an Interactive Voice Response Unit. A Responder serves as an interface to a database of pre-paid plan subscriber information, rates calls, and defines messages to be voiced by the IP. A Call Controller manages call context data for use by the Responder and conveys script information from the Responder to the IP. SS7 ISUP signaling enables out-of-band signaling between a carrier's MSC and the ISUP Application.