Here's how it works: Check in 24 hours before your flight using United's app and you'll be able to scan your passport using the camera on your phone/device. After it has been verified through a security company, you can print out your ticket, skip the check-in counter at the airport and head straight to security.
"The new passport-scanning feature saves valuable time and provides customers with more options to control their travel experience," Scott Wilson, United's vice president of merchandising and e-commerce, said in the announcement.
United says the new app feature, rolled out in a testing phase, was being used by passengers within an hour of the announcement. The airline will be collecting feedback from customers to see how well it's working.
Note too that United stores your scanned passport information in its system so it can be accessed or updated for any subsequent times you fly.
But don't think that this means you can just leave your passport at home now. You still need to present your documents at airport security checkpoints and before boarding the plane. And fliers visiting countries that require visas or other entry permits will still have to go to the check-in desk to receive a ticket.