To quickly and also exactly perform the issuing of a customer card and registration work of customer information.

An information processor 1 adopts a uniquely ascending customer number in a system through a customer number adopting means 14 and makes a printer 11 print a bar code that is made of the customer number on a customer information registration form 3. A bar code reader 21 on a register side reads a customer number that is attached in a bar code to the form 3, the register 2 outputs the customer number to a customer card reader-writer 22, and the reader-writer 22 writes the customer number on a customer card 4. The processor 1 reads a customer number that is attached in a bar code to the form 3 through a bar code reader 12 on the processor 1 side, associates it with customer information such as a customer name and a customer address written on the form 3 and records it on a customer information file 13.