China's payment market is not simply cashless. It is layered. UnionPay is the broad domestic card rail, mobile wallets dominate many everyday transactions, international cards work best where their logos are displayed, and renminbi cash remains legal tender and an official fallback.
Give each rail one clear job
UnionPay is the local passport
UnionPay cards issued outside the mainland have especially broad acceptance at mainland point-of-sale terminals. Visa, Mastercard, American Express, JCB and other cards depend on the logo and merchant setup. A terminal that accepts a local bank card is not automatically configured for every foreign card.
Cash is legal, but exact change is still practical
China's current cash-payment rules protect the public's right to choose legal payment methods and prohibit businesses from refusing renminbi cash in ordinary circumstances. That legal right does not manufacture change in a tiny kiosk. Carry 10- and 20-yuan notes alongside a few 1-yuan pieces.
Build a deliberately small cash pouch
Make the ATM show its network first
Use a machine displaying Visa, Mastercard, UnionPay or the network on your own card. Shanghai's official visitor guidance notes that individual machines commonly impose a per-withdrawal limit and your issuer can add a separate limit or fee. A bank-attached machine offers a clearer place to ask for help.
Keep the withdrawal in yuan
If an ATM offers to convert the withdrawal into your home currency, read the rate and markup carefully. Continuing in CNY usually leaves conversion to your own network or issuer. Your card can still have foreign-transaction or cash-advance fees, so check it before the trip.
Twenty thousand yuan is the border line
China Customs lists RMB 20,000 as the amount at which cash carried into or out of the country enters declaration rules. A normal travel wallet should be far below that, but the limit matters for group funds, long stays and anyone tempted to solve digital uncertainty with a very large envelope.