Abstract: A method and an apparatus for routing a service request in a telecommunications system. A location server (LS) stores a service identifier (SID) which identifies a service hosted in an application server (AS) and addressing information (AI) usable for routing a service request (f2,g3,h2) towards the application server. The addressing information can comprise an address of the application server, or an address of a communication server which can intervene in the signaling of said service. Before providing the addressing information, the location server checks a usage rule (UR) determining if said addressing information can be used for routing. The routing of a service request can be blocked (f6,g5,h7,h8) if said check is not passed. The usage rule can alternatively be downloaded (g2,h2a,h5b,f1a,g1a,h1a) in a communication server (CS) and be checked there, and can comprise one or more use conditions (T1,T2,T3,M,U) that can be determined by the concerned application server.