according to the query of unionpay POS machine processing center, first of all, we need to know the working principle of pos machine. POS machine is a kind of terminal equipment with the functions of card reading, storage, calculation, display and communication, which can be used for bank ka card transaction, consumption and inquiry. When spending by credit card, POS will read the information on the bank card, including card number, expiration date, CVV and other information, and then send these information to the bank for verification, and finally complete the payment. We can draw a conclusion that it is possible to make payment by directly inputting the bank card number into the POS machine. However, it should be noted that it is necessary to ensure that the card number is entered correctly, otherwise the payment may fail or the funds may be defrauded. In addition, some POS machines may not support direct input of bank card number for payment, and need to insert a bank card or use other payment methods.

POS(Pointofsales) means "point of sale" in Chinese, which is called point of sale information management system. It is a terminal reader equipped with bar code or OCR code technology and has the function of cash or barter line teller. Its main task is to provide data services and management functions for commodity and media transactions, and to carry out non-cash settlement. POS is a multifunctional terminal. It can be installed in the special merchants and accepting outlets of credit cards and connected with computers to form a network, so that electronic funds can be automatically transferred. It has the functions of supporting consumption, pre-authorization, balance inquiry and transfer, and it is safe, fast and reliable to use. It is difficult to obtain basic business information in bulk transactions, and the introduction of POS system is mainly to solve the blind spot of retail information management. An important part of chain branch management information system.