Cards can be swiped. Most stores in Hong Kong support credit cards, and many of them are equipped with UnionPay machines, which can swipe domestically issued credit cards. However, domestically issued credit cards are not supported for "mall installment payment" directly, which means that you still have to pay the full price in one go when making a purchase. But you can wait until you come back, log in to China Merchants Bank online banking, and apply for "bill installment", that is, apply for a one-time payment to be divided into 3, 6 or 12 repayments, and bear the corresponding handling fees. Assume the total price is 4,200 yuan. After swiping the card, you apply for 12 bill installments. The handling fee for each of the 12 installments is 0.66%. Then the monthly repayment amount is 4,200÷12+4,200×0.66%=377.72 yuan.