A method and apparatus for enabling customer premise Public Branch eXchange (PBX) service feature processing to be performed in a service provider network are disclosed. For example, the method receives a signaling message associated with a user by an application server deployed in a communication network, and accesses a customer premise Internet Protocol (IP) Public Branch eXchange (PBX) to retrieve customer premise IP PBX based service logic and data associated with the user by the application server. The method forwards an updated signaling message by the application server to a Serving Call Session Control Function (S-CSCF) network element for completing a service feature associated with the service logic and data in the communication network.