It isn't one QR code — it's two, running opposite ways

Visitors are often told "one QR code runs the whole trip." That's not quite right, and the difference matters the first time a payment stalls. There are two codes, and they travel in opposite directions.

1. Your payment code — the one you show

Inside Alipay or WeChat: a QR (and a barcode) that belongs to you. At a counter, you open it and hold the phone out; the shop points a scanner at your screen and the money leaves your account. It refreshes periodically, which is why a screenshot of it is useless — it's a live code, by design. Larger amounts may ask for your PIN.

This is the one to find on day one. Both apps keep it one tap from the home screen — Alipay calls it 付款码 (Pay), WeChat calls it 收付款.

2. The merchant's collection code — the one you scan

The printed square taped to the counter, the card on the table, the sticker in the window. You scan it, you type the amount, you confirm. The money arrives in their account. These are static, and they belong to whoever printed them — a stall, a taxi driver, a temple donation box.

Both directions happen in the same day. Supermarkets and chain shops scan you. Market stalls and small vendors usually want you to scan them.

And the merchant codes are all different

This is the part people don't expect. There is no single national QR. A shop displays its own code from whichever platform it signed up with — Alipay's, WeChat's, sometimes a bank or UnionPay one, sometimes two stickers side by side. Small places print one platform and nothing else, so your app may refuse to read what's on the counter. When that happens: ask if they have the other one, hand over cash, or go next door. Nobody is being difficult; the code is just theirs.

Everything else that looks like a QR

• Menu and ordering codes on the table — scan, order in-app, pay in-app.
• Mini-program codes — the round, colourful ones that open a service inside the app: metro, museum reservations, delivery.
• Friend, group and official-account codes — social, not payment. Scan one and you've joined something, not bought something.
• Ticket and reservation codes — static, and the only ones worth screenshotting.

What you can and can't screenshot

Tickets, reservations and the Arrival Card QR: screenshot them, email them to yourself, print them if you like. Your payment code: no — it rotates. A screenshot of it is a photo of something that no longer exists.

The rest of the risks are the ordinary ones: screen brightness, dead battery, no signal. Carry the power bank and keep some cash for the hour the phone gives up. Getting the apps ready in the first place is the job you do on home wifi before you fly.