An IC-card is a memory card that can be substituted for existing magnetic-striped cards. It is suggested that the IC-card, which can store various information for telephone calls, will become a useful device in multifunction telephone sets because of its portability, security, and large memory capacity. The information that should be stored on an IC-card is discussed, and the practicality of creating personal telephone services by combining telephone services with the stored user information is addressed. An experimental telephone set with an IC-card reader/writer developed to verify feasibility is presented. Service grades of IC-cards, according to their level of functionality versus the functionality of the terminal equipment, are discussed.<<ETX>>