PURPOSE: To attain addition or deletion relating to a subscriber telephone call from a terminal equipment itself or revision relating to service content by inputting a service class code number and a telephone number from the subscriber telephone terminal set, combining an accommodation location data of the subscriber terminal equipment to the data and using an automatic callback function so as to confirm the revised data.

CONSTITUTION: A beep tone requesting dialing of a service class code or release code is sent from a telephone terminal set, and the code number dialed by the caller is subject to reception processing. In case of dialing a caller service class code, the data registration or revision processing and check of the terminal set are applied. When the result is normal, the revision of the data is finished. If the processing is faulty, the registration/revision processing is invalidated to protect the data before the revision request and sends a reorder tone. Thus, the data revision and verification test of the telephone set are unified and the terminal connection to the electronic exchange system is simplified.