An improved decoding, processing and delivery system in a PBX for the advanced determination and display of geographic information to a called party relating to the call origination party. The improved system comprises a receiving device to receive the calling number delivery (CND) message from a switching center; a central database server at the PBX for storage and retrieval of specific data from a library for selectively determining the corresponding geographic information of the call origination party; a transmission device for sending data from the server over the station-telephone connectivity plane; a receiving device in a telephone; and a readout device for displaying the geographic information of the incoming call. Accordingly, the improved system provides the user with convenient and efficient display of geographic information related to caller identification that is capable of determining an ever-increasing number of area code and local telephone exchange number.