A passenger scans QR code to buy ticket at a station of subway Line 9 in Shenzhen, south China, Nov. 20, 2017. The Line 9 of Shenzhen subway started to allow passengers to pay for their tickets via WeChat or Alipay at its stations on Monday. The new payment method is expected to be available at Line 1, 2, 3, 5 and 7 in the future. (Xinhua/Mao Siqian)

A man uses a self-service ticket machine at a station of subway Line 9 in Shenzhen, south China, Nov. 20, 2017. The Line 9 of Shenzhen subway started to allow passengers to pay for their tickets via WeChat or Alipay at its stations on Monday. The new payment method is expected to be available at Line 1, 2, 3, 5 and 7 in the future. (Xinhua/Mao Siqian)