Abstract: A system and method for feature-based service control using Session Initiation Protocol (SIP) in an Internet Protocol Automatic Branch Exchanges (IPABX) system is described. The system and method include a new Event package and new Enhanced SIP methodsto control information for various feature-based services like wakeup alarm, call forwarding, voicemail configuration, and other services provided by traditional PBX systems. A user provides input to a client device to activate or deactivate feature-based services. In response, the client device sends a message to the IPABX server to activate or deactivate the feature-based service(s). The IPABX server then notifies the client device that the feature based-service(s) have been activated or deactivated.