Abstract: A business transaction processing system includes a server into which a purchasing information of a stockist, at a time when goods are supplied to a stockist from a plurality of suppliers, is inputted, and a supplier side terminal unit connected to the server through cable communication or wireless communication. The server is provided with a conversion unit for extracting purchasing data relating to an optional supplier of the suppliers from the purchasing information of the stockist and converting the extracted purchasing data into supply information of the optional supplier, and the supply information in the server is indicated on the supplier side terminal unit.