Check out in a duty-free app

Duty-free check out demands are a slightly different: there is no delivery option, you can't pay online, but you must add your flight information to receive your order.

Firstly, you enter your flight number and select your departure date/time OR scan the boarding pass to have it uploaded automatically. Then, the app needs only your name and a phone number to send you and SMS when the order is ready for you to pick up. When you're done with the check out, you see a "congratulations" screen that sums up the information about your order.

Do you think scanning a boarding pass is a good solution? Any thoughts are welcome :)