"I don't even have to bring a mobile phone with me, I can go out and do shopping without taking anything. This was not possible either at the earliest stage of mobile payment – only after the birth of facial recognition technology can we complete the payment without anything else," says Bo Hu, chief information officer of Wedome bakery, which uses facial payment machines across hundreds of stores.
The software is already widely used, often to monitor citizens. But authorities have come under fire for using it to crack down and monitor dissent.

"There's a big risk ... that the state could use this data for their own purposes, such as surveillance, monitoring, the tracking of political dissidents, social and information control, ethnic profiling, as in the case with Uighurs in Xinjiang, and even predictive policing," says Adam Ni, China researcher at Macquarie University in Sydney.

This is certainly one of the more contentious aspects of the gathering of facial recognition data and the usage of them. Despite the concerns over data security and privacy, many consumers seem unperturbed by facial recognition payment in the high street.
Alipay – the financial arm of ecommerce giant Alibaba – has been leading the charge in China with devices already in 100 cities.

The firm is predicting enormous growth in the sector and recently launched an upgrade of its "Smile-to-Pay" system, using a machine roughly the size of an iPad. Alipay will spend three billion yuan ($420m) over three years on implementing the technology.

Tencent, which runs the WeChat app with 600 million users, unveiled its new facial payment machine called "Frog Pro" in August, while a growing number of start-ups are trying to tap into the burgeoning industry.

"Facial payment certainly has the potential to become popular with the wide push from major mobile payment players. Alipay is spending billions to popularise facial payment technology through giving out subsidies for vendors and rewards for consumers that use facial payment." says Mengmeng Zhang, an analyst at Counterpoint.

At the IFuree self-service supermarket in Tianjin, a 3D camera scans the faces of those entering the store – measuring width, height and depth of the faces – then another quick scan again at check-out.

"It's convenient because you can buy things very quickly," says retiree Zhang Liming after using facial payment for her groceries."It's different from the payment in the traditional supermarket, in which you have to wait in the checkout line and it's very troublesome," she argues.