To provide a settlement processing system which perform settlement processing accompanying the purchase of an article or service by using a portable terminal that a user always uses and feels inconvenient when not carrying.

This system is equipped with an Internet WEB server 2 which stores personal information including the ID and password of a customer and an identification code decided corresponding to the personal information, a portable telephone 7 which has a communication function for acquiring the identification code by logging in on the WEB server by inputting the personal information through the Internet and a display screen 6 displaying the acquired identification code, and an input terminal 11 which is equipped with a read means 8 for reading the identification code displayed on the portable telephone 7 and an input means 9 for inputting settlement processing contents regarding a transaction and outputs or transmits the identification code and settlement processing contents, and a settlement system server 15 which connects to the input terminal 11, inputs the identification code and settlement processing contents outputted by the input terminal, stores a settlement account that the customer previously specified corresponding to the identification code, and perform settlement processing of the settlement account according to the settlement processing contents.