Asynchronous payment method and system based on user-specified payment information

An asynchronous payment method based on user-specified payment information, the payment method comprising the steps of:

• allowing a user to pre-register information of at least one or more payment types onto a payment server;
• allowing the user to select one of the at least one or more payment types whenever the user purchases a product or service in a shop system, to input prearranged payment registration information including payment amount limit and payment expiration time determined according to the product or service to be purchased by him or her to the payment server, and to request prearranged payment registration through which payment is activated with the selected payment type during the payment expiration time;
• if a prearranged payment registration serial number matching the prearranged payment registration information is generated and received according to the prearranged payment registration, allowing the user to input the prearranged payment registration serial number to the shop system to request the purchase for the product or service;
• and
• if the prearranged payment registration serial number and payment information including payment amount are transmitted from the shop system to the payment server within the payment expiration time, allowing the payment server to perform payment processing according to whether the prearranged payment registration information matches the payment information.