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 equipped with chips, and direct card swiping in domestic POS machines that support UnionPay often fails to read. The correct card swiping posture is to insert the chip first, and then slide immediately when the unreadable information is displayed, so that the reading can basically succeed. 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 can't be swiped unless it already supports foreign cards.