A method and apparatus for a payment service are disclosed. A method of operating a server providing a payment service includes obtaining country-related information of a terminal connected to the payment service. The country-related information of a terminal may include a country code the number of the terminal is assigned to. The method includes providing an international credit card as an option for a payment method to the terminal based on the country-related information. The method includes checking whether an account corresponding to the terminal is authenticated. The method includes determining a default value of a payment method corresponding to the account based on whether the account is authenticated.