Abstract: The present invention provides a method and system for access control in an open service architecture, preferably a Parlay architecture. A framework entity includes or co-operates with a gateway entity. A client application intending to use a service of the open service architecture signs a service agreement with the framework entity which then sets the rules for the gateway entity accordingly. The gateway entity controls the service use in accordance with the signed service agreement. After expiry of the service agreement, the gateway entity inhibits further use of the service by the client application. The framework entity and gateway entity may preferably be arranged within the same network equipment.