Mobile pay is taking China by storm and changing daily commerce. The transformation of a society limited to bills denominated in 100 yuan ($15) or less into one where QR payment codes abound was by far the biggest change in mainland China since my last visit four years ago.

When eating out or shopping with local friends, they paid by scanning a QR code on the restaurant table or by showing a similar code on their smartphones to the store clerk. A spices shop, museum souvenir store and seller of traditional Chinese calligraphy brushes all had signs saying they accepted mobile pay. Rather than, “Do you take credit card?” the question was often “Do you take Alipay? WeChat Pay?” The running joke was that street beggars would rather take a mobile donation rather than cash.