Discover's exchange rate is calculated according to the foreign exchange quotation implemented in China, which can generally be used in POS machines or ATM machines with UnionPay channels. Discover can indeed take the UnionPay channel, but many UnionPay machines don't recognize chip cards, so you have to downgrade and brush the magnetic stripe.

At present, Discover cards are all with chips, so it is often impossible to read them directly on POS machines that support UnionPay in China. The correct swipe posture is to insert the chip first and slide it immediately when unreadable information is displayed, so that reading can be basically successful. Don't slide directly! Discover's card swiping in China is limited to UnionPay POS transactions, and three payment methods, such as apple pay, WeChat and Alipay, cannot swipe their cards unless they already support foreign cards.