Here's a question I'm hoping to get an answer to from this forum: to board a flight which involves a transit connection, with a plane change, at Incheon, does the passenger have to have at least 6 months validity left on the passport? The passenger is going to fly through without entering Korea immigration. The argument I've received in the not-so-distant past to justify such condition in case of another airport (KLIA) is that the passenger could simply try to enter Malaysia immigration instead of flying on through in which case 6 months validity is an entry requirement; denial of such entry on grounds of insufficient life left on the passport would put the airline on the hook. That might be an overly conservative approach, but trying to pre-empt nasty surprises after booking.