The ride code, the bag scanner, the exit letter: China's metro in three habits

Three habits separate a smooth week on Chinese city transit from a week of small, expensive detours: the code you pay with, the belt you put your bag on, and the letter above the stairs.

Pay before you're underground

Both Alipay (支付宝, Zhīfùbǎo) and WeChat Pay carry a transit code — 乘车码, chéngchēmǎ — and it is city-specific. A Shanghai code will not open a Chengdu gate. Add the cities on your itinerary while you still have hotel wifi, along with whatever connection tools you intend to use; configuring anything after you land is harder than configuring it before.

Foreign cards bind directly to Alipay now, but the process wants your passport and a verification step, and neither is quick with a queue behind you. Do it over breakfast on day one and test it on something small, a bottle of water. Staffed ticket windows still take cash in every city. Slower, never wrong.

The belt at the entrance

Every metro station in mainland China screens bags. Backpack on the belt, walk through, collect it: eleven seconds if you have already unslung it, two minutes if you are working that out at the machine. Staff may ask you to drink from your own water bottle, so carry it where you can reach it. Lighters and aerosols are the usual casualties.

The letter above the stairs

Beijing, Guangzhou and Shenzhen letter their exits — A, B, C, D — and Shanghai numbers them. Either way the exit is part of the address: a restaurant will tell you 东直门 (Dōngzhímén), Exit B, and that is not decoration. Take the wrong one and you can surface across a road with no crossing for several hundred metres. The wall map on the platform lists what stands above each exit.

出站前先看墙上的出口示意图，选错一个字母，可能要多走十分钟。