Check-out system, including merchandise registration apparatus and payment apparatus, and electronic receipt management server

A check-out system for performing a check-out process, comprising:

• a receipt server including a memory that stores payment information associated with a user code;
• a registration apparatus including:
• a first communication unit;
• a first input device configured to receive input of merchandise information for merchandise items to be purchased in a transaction and receive input of a user code in connection with the transaction;
• and
• a first controller configured to:
• generate payment information based on the input merchandise information;
• when the user code is input in the first input device, control the first communication unit to transmit to the receipt server the generated payment information with the user code;
• and
• when the user code is not input in the first input device, control the first communication unit to transmit the generated payment information to one of a plurality of payment apparatuses;
• and
• each of the payment apparatuses including:
• a second communication unit;
• a second input device configured to receive input of the user code;
• and
• a second controller configured to:
• when the user code is input in the second input device, control the second communication unit to transmit to the receipt server a request for the payment information using the user code input in the second input device and receive from the receipt server the payment information associated with the user code, and process payment based on the received payment information;
• and
• when the user code is not input in the second input device, process payment based on the payment information received from the registration apparatus.