Domestic flights are the fastest way to cover Thailand's long distances: Bangkok to Chiang Mai, Phuket, Krabi, Koh Samui or Hat Yai takes a little over an hour in the air. The thing to get right is the airport. Bangkok has two, and the full-service and low-cost airlines are split between them.
A flight usually beats the overnight train or bus on time, and often comes close on price when booked early. It loses on the extras: getting to the airport, arriving two hours before departure and paying for checked bags on the cheapest fares. For a trip of under about four hours by road or rail, the train or a car is often just as quick door to door.
This page covers who flies where, how to pick the right Bangkok airport, what the carry-on rule is and why Koh Samui is a special case. Booking platforms are covered in our guide to 12Go.asia, which also lists flights next to buses and trains.
Domestic flights in Thailand at a glance
- Bangkok airports
- Suvarnabhumi (BKK) and Don Mueang (DMK), in different parts of the city
- Listed at Suvarnabhumi
- Thai Airways, Bangkok Airways, Thai AirAsia, Thai Vietjet (AOT airline directory, October 2026)
- Don Mueang
- Bangkok's low-cost hub, used by Nok Air, Thai Lion Air and Thai AirAsia
- Carry-on limit at the airport
- 56 x 40 x 23 cm and 7 kg (AOT, Don Mueang departure guide)
- At the gate
- At least 45 minutes before departure (AOT)
- ID
- An original identity document is checked at security; for foreign visitors that means a passport
The airlines flying inside Thailand
Thai Airways is the national carrier and flies domestic routes from Suvarnabhumi. Its former low-cost subsidiary Thai Smile no longer exists: it flew its last flights on 31 December 2023 and handed its domestic routes to the parent airline, according to the trade paper TTR Weekly. Blogs that still tell you to "book Thai Smile" are out of date.
Bangkok Airways flies from Suvarnabhumi and owns three airports of its own (more on that below). Thai AirAsia is the largest low-cost carrier, and Airports of Thailand (AOT) lists it at both Suvarnabhumi and Don Mueang, so check which one your ticket says. Nok Air and Thai Lion Air are low-cost airlines based at Don Mueang; neither appears in AOT's Suvarnabhumi airline directory. Thai Vietjet is listed at Suvarnabhumi.
One safety note from the UK Foreign Office: it says Nok Air has been suspended from operating international flights by Thailand's Civil Aviation Authority because of safety concerns, but still operates domestically. Read the FCDO's current advice before you book and decide for yourself.
Suvarnabhumi or Don Mueang: getting the airport right
The most expensive mistake on a domestic trip is going to the wrong Bangkok airport. Your booking shows a three-letter code: BKK is Suvarnabhumi, DMK is Don Mueang. Check it twice, especially on Thai AirAsia, which uses both.
Connecting from an international flight is easiest when both legs use the same airport. If they do not, AOT runs a free shuttle bus between the two, but only for passengers connecting between flights who can show an onward ticket and a passport; it is not for the general public. Allow plenty of time, because you need to collect your bags and check in again.
Our guide to Suvarnabhumi or Don Mueang explains the split in detail, and the transfer pages cover getting into the city from Suvarnabhumi and from Don Mueang.
BKK and DMK on the same itinerary means a separate check-in. If your international flight lands at Suvarnabhumi and your domestic flight leaves from Don Mueang, you collect your bags, cross Bangkok and start again. Leave several hours, not one.
The busiest domestic routes
Most domestic flying is from Bangkok to the north and to the beaches. These are the routes visitors use most:
| From Bangkok to | Why people fly | Ground alternative |
|---|---|---|
| Chiang Mai (CNX) | Saves a night on the train or bus | Overnight train, see Bangkok to Chiang Mai |
| Phuket (HKT) | Beaches and boats to Phi Phi | Long-distance bus |
| Krabi (KBV) | Ao Nang, Railay, Koh Lanta | Bus or train plus bus |
| Koh Samui (USM) | Direct to the island | Train or bus plus ferry |
| Hat Yai (HDY) | The deep south and the Malaysian border | Train |
| Chiang Rai (CEI) | The far north | Bus from Chiang Mai |
AOT itself runs six airports: Suvarnabhumi, Don Mueang, Chiang Mai, Chiang Rai, Hat Yai and Phuket. Others, such as Krabi and Surat Thani, are not AOT airports, and three belong to Bangkok Airways. For an overview of every gateway, see our guide to Thailand's airports; for the sleeper alternative to flying north, Thailand's night trains.
Koh Samui, Sukhothai and Trat: Bangkok Airways' own airports
You will often read that only Bangkok Airways flies to Koh Samui. That is too strong. Bangkok Airways owns and operates three airports, at Samui, Sukhothai and Trat, and Samui Airport opened in 1989 as a privately owned public airport. But the airline's own investor page says Samui's income includes ground handling "provided to other airlines using Samui Airport", so other airlines do fly there. What is true is that the airport is small, Bangkok Airways dominates it and fares are often high.
For Sukhothai and Trat, Bangkok Airways does state that it is the only airline flying in. Trat is the airport for Koh Chang, 387 km east of Bangkok, and Sukhothai is the gateway to the old capital (see our Sukhothai guide). The same Bangkok Airways page says the Trat airport licence was valid until 14 March 2026 and has not been updated since, so check the current schedule before you plan around a Trat flight.
Surat Thani plus the boat is the alternative to a Samui flight. Lomprayah sells connections from Surat Thani Airport to Koh Samui, Koh Phangan and Koh Tao. It takes longer than flying direct, so compare the total fare and travel time before you book. Our Koh Samui transport guide compares the options.
Baggage: carry-on limits and what your fare includes
AOT's departure guide for Don Mueang gives a carry-on limit of 56 x 40 x 23 cm and 7 kg. Individual airlines set their own allowances on top of that, and they vary by fare type, so the only reliable answer is the one printed on your booking.
On the low-cost carriers, the cheapest fare usually covers only the seat and a cabin bag; checked baggage is added when you book. Adding it online is normally cheaper than paying at the airport. Full-service fares on Thai Airways and Bangkok Airways generally include a checked bag, but the weight depends on the fare, so check before you pack.
Sports equipment such as surfboards, golf bags and diving gear is handled as special baggage with its own fees. If you are carrying medicines, our guide to prescription medicine in Thailand covers what to keep with you.
On the day: timing, check-in and ID
AOT asks passengers to allow at least two hours to get to Don Mueang, because Bangkok traffic is unpredictable, and to be at the boarding gate at least 45 minutes before departure. Online check-in, self-service kiosks and bag-drop machines are available, but bag-drop counters close before departure, so do not arrive at the last minute with a checked bag.
At security, staff check your boarding pass and an original identity document. Thai citizens use their ID card; foreign visitors need their passport, even on a domestic flight. A photo on your phone is not enough. Travelers from Singapore, Malaysia or China flying straight on to the islands can connect at Bangkok or fly direct to some regional airports; see flights to Thailand from Asia.
Frequently asked questions
Do I need a passport for a domestic flight in Thailand?
Yes. AOT says security staff check a valid original identity document along with your boarding pass. Thai citizens can use their national ID card, but foreign visitors should carry their passport. A photocopy or a phone photo will not be accepted.
Is Thai Smile still flying?
No. Thai Smile ended all flights on 31 December 2023, and its domestic routes were taken over by Thai Airways, which flies them from Suvarnabhumi. If a website still sells "Thai Smile" tickets, check the flight number and airline carefully before you pay.
Is Bangkok Airways the only airline that flies to Koh Samui?
Not quite. Bangkok Airways owns Samui Airport and runs most flights there, but its own investor page refers to other airlines using the airport. It is the only airline flying into Sukhothai and Trat, according to the airline. Flying to Surat Thani and taking the ferry is the usual cheaper alternative.
Which Bangkok airport do low-cost flights use?
Mostly Don Mueang. Nok Air and Thai Lion Air fly from there, and Thai AirAsia uses Don Mueang as well as Suvarnabhumi. Always check the airport code on your booking: DMK for Don Mueang, BKK for Suvarnabhumi.
Sources
- Airports of Thailand – Suvarnabhumi Airport airline information (checked October 2026)
- Airports of Thailand – Chiang Mai Airport airline information (checked October 2026)
- Airports of Thailand – Don Mueang departure procedure (checked October 2026)
- Airports of Thailand – Don Mueang International Airport (checked October 2026)
- Bangkok Airways Investor Relations – Airport business (checked October 2026)
- TTR Weekly – Thai Smile wraps up ops with final flight (January 2024) (checked October 2026)
- UK FCDO – Thailand travel advice: Safety and security (air safety) (checked October 2026)
- Lomprayah – Surat Thani Airport connections (checked October 2026)