Hi,
Planning to go to Bangkok in September and we are then going to Koh Samui. Can someone advise if the domestic and International airport are in the same complex . Need to allow appropriate time between flights. Thanks.

It will depend on the airlines. In your case if you are flying on Bangkok Airways or Thai Airways to Samui you will be flying in and out of BKK or Suvarnabhumi airport.

The other airport is DMK or Don Mueang and as of right now only serve Air Asia (both domestic and international), Nok Air and Orient Thai airways.

Just reread your question. For BKK there's one big building and no multiple terminals.

i agree with Hanuman for BKK there just one stop sadly no multiple terminals available

i would add that the distances are huge within the BKK airport, so it might as well be multi-buildings... it is a very pleasant airport however, well planned and laid out

Many thanks for your responses. We would arrive on Qantas then fly Bangkok Airways to Koh Samui. On our return to Bangkok we are flying to Kuala Lumphur with either Jetstar Asia or Malayasian Airlines . So looks like we would be at the same terminal but should allow a couple of hours between flights especially going to KL.