The Area Wide Centrex service is provided in a telephone communication network having a plurality of interconnected central office switching systems, each at a different location. Each of the central office switching systems connects to a number of local telephone lines, a number of which can be designated as members of a business group for a particular customer. Area Wide Centrex extends a number of service features to the business group over a broad area through multiple central offices by taking the programming intelligence capacity out of the central offices and moving it to a central point. Service features such as call routing are controlled by data stored in a central data base. Establishing or changing services for one or all of a particular customer's lines requires only reprogramming that customer's data in the central data base, without the need to reprogram each central office switch. Also, Centrex services such as extension number type intercom dialing and call transfer can be extended across provided to groups of lines connected to different exchanges.