To easily affiliate a customer as a member from a store side.

This data processor is provided with a communication part 26 for communicating with an electronic settlement terminal 3 and an information center server 4 having respectively communication functions, a printer 29a for outputting information, and a CPU 21 for receiving settlement information read by the electronic settlement terminal 3 when settled, via the communication part 26, from the electronic settlement terminal 3, for transmitting the received settlement information to the information center server 4, for receiving a temporary member ID and a temporary password generated correlatedly with the settlement information, from the information center server 4, via the communication part 26, and for outputting the received temporary member ID and temporary password to the printer 29a.