Domestic travel during public holidays and on weekends, particularly to popular destinations, should be booked well in advance for all modes of transportation. Booking is particularly difficult during the Songkran Holiday and New Year's Holiday.
Air : Local carriers Thai Airways(TG) and Bangkok Airways (PG) fly to most major provincial airports beyond 250 km distance from Bangkok. Thai Airways' 2 most popular routes are Chiang Mai and Phuket. Services to Koh Samui and Sukhothai are only provided by Bangkok Airways. Other smaller local carriers include Angel Air (mainly servicing Phuket) and PB Air which flies to fewer destinations. Air Andaman services is limited to the Southern cities only.
Check-ins for domestic flight is one hour prior to departure time and closes half an hour before flight time. Departure tax has already been added to your ticket fare.