Originally Posted by
IAN-UK
As I understand it, the OP's problem is not the arrival process, but about being accepted for travel by check-in staff at the origin.
I'm actually more concerned with immigration, as I'll be traveling with only a carry-on and expect to use online check-in and mobile boarding passes as much as possible. I fly on one-way tickets all the time in the Americas and have never been flagged for proof of onward travel using an airline's app. I hope the same is true for the airlines in SE Asia, but I suppose things could work differently there.
As long as countries have an onward travel clause in their requirements for entry, airlines will protect themselves from fines, and the costs of flying passengers back to the flight's origin, by checking details of onward travel. It's not a difficult concept to grasp.
Are you speaking from experience in SE Asia or just speaking generally? I believe several of my usual destinations (Panama, Mexico) technically require proof of onward travel, but I've only been asked by an airline once and I've never been asked for it by immigration in probably 30+ combined trips to those two countries. Thanks.