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, 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 a Serving Call Session Control Function (S-CSCF) network element. The method then completes a service feature associated with the service logic and data in the communication network.