A system and method for capturing and modifying roaming mobile subscriber information such as Serving MSCID, cell and sector location information, original dialed digits, subscriber profile and return address point code in support of service applications, such as wireless prepaid service for roaming subscribers. A network platform is inserted into the signaling path between a roaming subscriber's HLR and all Serving MSCs. The network platform intercepts messages exchanged between the roaming subscriber's Serving MSC and HLR, and extracts and stores information such as Serving MSCID, cell and sector data. The network platform may also modify the exchanged messages in support of service applications.