二维码互通
mutual acceptance of QR code

12月1日起，北京、上海地铁乘车二维码实现互联互通。

The service, effective on Tuesday, allows the QR code on the respective apps in Beijing and Shanghai to be accepted for payments in the subway system of both cities.
自12月1日起，北京和上海的地铁乘车二维码均可用于两市地铁系统票款支付。