Well in China people also scan QR stick on the wall when exiting the parking lot...

_-___________-_ · on Oct 27, 2020

> You could start paying while you are in the line by scanning the QR

You can save them in the app and not have to scan every time too. It's pretty common at people's regular lunch places for them to pay while they wait in line. There's no deep technical reason this couldn't be implemented with the card system either, of course.

luckylion · on Oct 27, 2020

How does the shop know who paid? Do they then check your phone screen for the correct verification code that matches their transaction?

_-___________-_ · on Oct 27, 2020

At the kind of shops I'm thinking of, they just look at the amount you paid and make sure it matches what you're ordering.

seanmcdirmid · on Oct 27, 2020

I pay for Starbucks on my phone while ordering also. No QR code scanning involved.