COMMUNICATION TERMINAL DEVICE, CARRIER SERVER, METHOD, AND PROGRAM

PROBLEM TO BE SOLVED: To make the same cellphone unit usable even if carriers are different. SOLUTION: In a SIM card 12 mounted on a cellphone unit 10, information of plurality of carriers and selection information of one or more carriers selected from a plurality of carriers are stored in addition to an identification number and a phone number of a user. When personal identification is executed between the SIM card 12 and itself, a CPU 11 of the cellphone unit 10 transmits a service request to a carrier server 20. In accordance with its reply, a contract of service provision is concluded between the user and the carrier. COPYRIGHT: (C)2009,JPO&INPIT