Upvote:1
For the US citizens, the airlines allow submitting the passport information through their apps (United) or self-serve kiosks (Delta), at least based on my personal experience, and in-person check in is not required. The security check before the boarding gates is still required for everyone though (for US citizens they check that you have the passport there, but I'm not sure if all the airlines do that - I've only experienced it with United).
For green card holders and other non-US people, the airlines are required to verify that you have the necessary documentation when you board. US citizens cannot be deported, everyone else (including LPRs) can be denied entry and flown back at the airlines' expense if they lack proper documentation. The only way to verify that they do in fact have that documentation is to physically inspect it at the airport (including prior to boarding, but it's cheaper and more efficient to do it at check-in since the facilities are all there already).
I had similar experience with other countries as well. For example, I needed to go through documents check on my flights to China (visa required) before boarding. I believe they also forced me to check in in person then. On the way out of China the Chinese immigration authorities perform the check. You can't leave the country if you don't have entrance visa/permit to your destination.
Upvote:1
Iberia allows you to upload documents in advance (e.g., ESTA or Green Card, Covid-vaccination or Covid test result, ...). Then, these documents get checked and once verified, you can print out your boarding card at home.
Upvote:2
I'm a US citizen, and flew KLM from Amsterdam to the US a month ago. After submitting a variety of covid-related documents online, KLM issued me a boarding pass a few days before the flight.
Upvote:5
United Airlines will absolutely let a US Permanent Resident (Green Card holder) check-in online for a flight to the US - although it is not always successful.
For this to be successful you will need to meet a few conditions.
After doing the above, you will generally be able to check-in, and you MAY be issued with a boarding pass. There is no way to know in advance if you will be given a boarding pass or not. In the few years prior to COVID when travelling on a visa I was maybe 75% successful at being able to check-in online for flights to the US. Since having a greencard I've been 100% successful - but that's from exactly 1 attempt so not necessarily all that meaningful.