From groceries to cab rides, most smartphone users in China are used to paying for their purchases with mobile apps.

But there’s a catch to all that convenience: It requires an internet connection. So what happens when you don’t have one, say... in a plane cabin without Wi-Fi? In China, that would usually mean you have to put your phone back into your pocket and whip out cash instead.

That’s because the country’s two most popular payment apps, Tencent’s WeChat and Alibaba’s Alipay, both rely on QR codes.

(Abacus is a unit of the South China Morning Post, which is owned by Alibaba.)

There are two ways to pay with QR codes. One is to scan the merchant’s code, which requires a web connection to Alipay’s or WeChat’s servers. The other way is to let the seller scan your personal code. The code can be generated offline, but the merchant still needs an internet-connected terminal to process the payment.

So either way, at least one side needs to be online to complete a transaction.

WeChat is now finally trying to change that by experimenting with offline payments on flights.

(Picture: WeChat Pay via Weibo)

From now until Sunday, passengers of two Spring Airlines flights between Shanghai and Chengdu can sign up for the trial service before boarding. Successful registrants can use WeChat to purchase food and beverages, souvenirs, blankets and in-flight services on the plane. The bill will be stored on the app until the flight lands. When the device connects to the internet again, the payment is automatically deducted.

WeChat says it plans to expand the new payment service to more flights, but not every WeChat user can use it. Only those with scores above 550 in WeChat’s commercial social credit program are eligible.

Not to be confused with the government’s official social credit systems, Alipay and WeChat run their own credit initiatives that are more akin to the West’s private financial credit score. Users who opt in are scored based on their purchase history and financial behavior, such as whether credit card or utility bills were regularly paid on time.

High scorers enjoy advantages like deposit-free car rentals. Some countries also accept Alipay’s Zhima Credit as supporting information for visa applications from Chinese citizens, including Canada, Argentina and Latvia.