Can an airline at Bangkok airport require proof of an onward or return ticket at check-in?

Travelers report that check-in desks in Bangkok often ask for proof of a return or onward flight, including on departures to countries other than Thailand. Keep the itinerary on your phone and ideally save an offline PDF.

The check is inconsistent and depends on the airline and the individual agent: one traveler was asked only twice in eight years. A previous trip without a check is not a guarantee, so arrange valid proof before reaching the desk.

The airline, rather than immigration, may perform the check at check-in because it can be responsible for transporting a refused passenger back. This is especially relevant for visa-exempt arrivals, so use a genuine, verifiable onward ticket.