Foreigners visiting China are increasingly stumped by its cashless society

Technically, it's illegal for Chinese merchants to refuse payment in cash, but this rule is hardly ever enforced, and China has been sprinting to a cashless society that requires mobile devices -- not credit-cards -- to effect payments, even to street hawkers.

This has lots of implications for privacy, surveillance, taxation, and fairness, but in the short term, the biggest impact is on visitors to China, who are increasingly unable to buy anything because they lack Chinese payment apps like Wechat, and even when they install them, the apps' support for non-Chinese bank accounts and credit cards is spotty-to-nonexistent.

This is also affecting Chinese people, of course: some elderly people who have been slow to embrace mobile devices are finding themselves frozen out of the system, offering cash to passersby to buy them goods from vending machines. There are also refuseniks who are equally locked out.

Tourists are increasingly corralled into guided tours, with paid guides who make purchases on their behalf. The Wall Street Journal piece on the phenomenon quotes a Chinese executive who proposes that the unique Chinese obsession with QR codes (and mobile payments) is itself a reason to visit China, offering tourists a glimpse into another culture.

Travelers have had more luck on Alipay, which introduced a seven-step process last week that requires visitors to submit passport and visa information to Alipay, before loading money using an overseas card onto a prepaid card.

In a bathroom near the Great Wall recently, Catherine De Witte, a Belgian marketing consultant, was getting frustrated.