PURPOSE: To delete or revise subscriber data in a speech state without affecting the speech state by providing tentatively the subscriber data to a pseudo terminal equipment when a delete object subscriber is busy so as to delete registration of a subscriber number or the like from a subscriber data file.

CONSTITUTION: The system is made up of subscriber terminal equipments A, B connected via a switch 103, and a control circuit 104 controlling transmission reception sections 101, 102 or the like by using a data memory 105 and a program memory 107. Through the constitution above, when subscriber data of a busy subscriber are deleted, a pseudo terminal equipment not in use at present is set in cross reference with a normal number provided to the subscriber. While the subscriber data are saved and stored in the pseudo terminal equipment, a subscriber number and a subscriber accommodated position in the subscriber data are deleted from a subscriber data file. When the speech is finished, the normal number in cross reference with the pseudo terminal equipment is deleted and the subscriber data are deleted.