If you need to buy a China Unicom contract machine, then as long as the available balance of your own deposit in your bank card is greater than or equal to 5,499 yuan. You can make a one-time payment when you swipe your card, but when the bank makes installments, you can choose to make installments of the actual deducted credit limit (5,000 yuan). However, different banks may have different regulations. For details, it is recommended that you consult the online customer service at www.10010.com of China Unicom or the official customer service of the bank.