A settlement system comprising: a server comprising: a rate notification unit configured to report, at a predetermined occasion, an exchange rate between a currency of a first country and a second country, wherein the settlement system also comprises a merchant device, the exchange rate is applicable for a predetermined period of time to the merchant device, the server comprises a payment controller configured to perform control to determine an amount of payment to be made to the merchant device, based on sales information reported by the merchant device and an exchange rate at a time of purchase, and pay the determined amount to the merchant device in a currency of a second country, the currency of the second country being a home currency for the merchant device, the merchant device comprises: a display controller configured to, if a request from a mobile terminal apparatus of a user is received, perform control, based on a fixed exchange rate reported by the server, to display on the mobile terminal apparatus of the user an amount of payment for purchase of an article in a currency of a first country designated by the user; and a sales notification unit configured to, if the user purchases the article, notify the server of the sales information in the currency of the first country, the sales information being calculated by the display controller based on the exchange rate reported by the server, the display controller performs control in such a manner as to identify, based on receipt of an image of an article that the user wishes to purchase from the mobile terminal apparatus, a price of the article contained in the image, calculate the amount of payment for purchase of the article in the currency of the first country based on the price of the article and the exchange rate, and display the calculated amount of payment on the image. a server comprising: a rate notification unit configured to report, at a predetermined occasion, an exchange rate between a currency of a first country and a second country, wherein the settlement system also comprises a merchant device, the exchange rate is applicable for a predetermined period of time to the merchant device, the server comprises a payment controller configured to perform control to determine an amount of payment to be made to the merchant device, based on sales information reported by the merchant device and an exchange rate at a time of purchase, and pay the determined amount to the merchant device in a currency of a second country, the currency of the second country being a home currency for the merchant device, the merchant device comprises: a display controller configured to, if a request from a mobile terminal apparatus of a user is received, perform control, based on a fixed exchange rate reported by the server, to display on the mobile terminal apparatus of the user an amount of payment for purchase of an article in a currency of a first country designated by the user; and a sales notification unit configured to, if the user purchases the article, notify the server of the sales information in the currency of the first country, the sales information being calculated by the display controller based on the exchange rate reported by the server, the display controller performs control in such a manner as to identify, based on receipt of an image of an article that the user wishes to purchase from the mobile terminal apparatus, a price of the article contained in the image, calculate the amount of payment for purchase of the article in the currency of the first country based on the price of the article and the exchange rate, and display the calculated amount of payment on the image. a display controller configured to, if a request from a mobile terminal apparatus of a user is received, perform control, based on a fixed exchange rate reported by the server, to display on the mobile terminal apparatus of the user an amount of payment for purchase of an article in a currency of a first country designated by the user; and a sales notification unit configured to, if the user purchases the article, notify the server of the sales information in the currency of the first country, the sales information being calculated by the display controller based on the exchange rate reported by the server, the display controller performs control in such a manner as to identify, based on receipt of an image of an article that the user wishes to purchase from the mobile terminal apparatus, a price of the article contained in the image, calculate the amount of payment for purchase of the article in the currency of the first country based on the price of the article and the exchange rate, and display the calculated amount of payment on the image.