A telecommunications system determines a telecommunications service provider's routing preference for routing a call for a subscriber. The telecommunications system includes a storage that stores call routing data and a call routing service application for determining the routing preference using the call routing data. The call routing data includes an indicator that indicates when the subscriber subscribes to resold local switching services and when the subscriber subscribes to unbundled local switching services. The telecommunications system also includes a processor that executes the call routing service application, and that generates call routing instructions for routing the call according to the determined routing preference.