China is the workshop of the world's checkout counter. Two Shenzhen firms, PAX and NEXGO, rank among the largest payment-terminal makers on earth by units shipped, between them tens of millions of devices across more than a hundred countries.
The product has moved up the stack. It began as a countertop EFT-POS box with a PIN pad; since PAX shipped its first Android smart terminal in 2016, the category has become Android SmartPOS, a touchscreen computer with camera, scanner and an app store, spanning mPOS dongles, handhelds, desktop ECRs and facial-recognition units.
The moat is certification, not plastic. Anyone can mould an Android tablet. What these houses own is the secure platform: EMV scheme approval, PCI PTS tamper-resistant hardware, the newer PCI MPoC / SoftPOS standards, secure key injection, and the patience to carry a design through every regional acquirer's lab. That certified core, plus global certification support, is what you are really paying for.
Geography: Shenzhen holds the dense core (PAX, NEXGO); Foshan is the Pearl-River sibling, strong in biometric and face-recognition POS and self-service kiosks. The other Chinese majors sit outside the Delta, Newland and Landi in Fuzhou, Sunmi in Shanghai, and are out of scope here.