Thai Airways International and Thai Smile Airways have asked passengers to arrive at Suvarnabhumi airport earlier during this week's Apec summit in Bangkok.
With leaders of many countries touching down in the capital, the airlines posted notices online asking passengers to cater for potential delays en route.
They suggested that those on international flights should arrive at least three hours prior to takeoff and domestic travellers allow two hours before departure.
Ticketholders are also urged to check both carriers' websites prior to leaving.
