Buses from Bangkok to Koh Chang
If you want to travel from Bangkok to Koh Chang by bus, then you should take it from Ekkamai Bus Station at Bangkok’s Eastern Bus terminal which is the closest from Suvarnabhumi Airport or from Mo Chit Station at the Northern terminal.
The Government Buses 999 from Ekkamai Bus Station are in a very good condition and they provide a free snack and drink during the trip. They will also stop for a toilet break and a longer time where you you can buy snacks, drinks or food.
There is no need to buy the tickets in advance, you can do it directly at the station 20-30 minutes before the departure. But if you want to be sure and prefer to book it online, visit: https://www.busonlineticket.co.th/bus/bus-999
Buses ran by Tanakawee or 99 Express go directly to Ao Thammachat and Centerpoint ferry piers. Others will go to Trat Bus Station which is about 1km away from the town. There will be taxis ready to bring you to the ferry piers. It will cost between 200 and 300 Baht depending if you take a private or a shared taxi.
If you are arriving at Suvarnabhumi Airport, you will need to take the free shuttle bus from the airport terminal going to the “Transportation Terminal” aka Ekkamai Bus Station. Ask the driver before if you are not sure.
It will take about 7 hours to reach the piers or Trat. The price of the government bus is about 260 Baht per way and per person. They will propose you to buy the ferry ticket at the same time. It’s exactly the same price than at the piers, it’s up to you.
Night Bus from Bangkok to Koh Chang
There is one night bus which is departing from Ekkamai Bus Station at 23:30 to arrive at Trat Bus Station at 5:00. Because there is less traffic by night, it takes less than 6 hours.
This night bus will stop at Trat Bus Station. You will then need to take a taxi to the piers and you will be able to catch the first morning ferry.
Timetables of the different bus companies
Ekkamai to Ferries
Ferries to Ekkaimai 06:30, 07:45 and 09:45 12:30, 14:00 and 16:00
Ekkamai to Trat
Trat to Ekkaimai 06:00, 07:00, 09:30, 11:00, 12:30, 13:15, 14:00, 15:30, 17:30, 19:30, 20:30, 22:00, 23:00 and 23:30 07:00, 08:00, 09:00, 9:30, 10:00, 11:00, 12:00, 13:00, 14:00, 16:00, 18:00, 21:30, 23:00 and 23:30 Mo Chit to Trat (via Suvarnabhumi Airport) Trat to Mo Chit (via Suvarnabhumi Airport) 8:30 and 17:30 8:30 and 14:30
Ekkamai to Ferry (Ao Tammachat pier) Ferry (Ao Tammachat pier) to Khao San Rd. 08:30 11:30 Ekkamai to Trat Trat to Ekkamai 10:30, 12.00, 16:40, 18:30 and 22:30 10:00, 10:30, 12:00, 14:00 and 20:00 Mo Chit to Trat (via Suvarnabhumi Airport) Trat to Mo Chit (via Suvarnabhumi Airport) 06:00, 09:30, 12:30, 15:30 and 23:00 07:30, 09:30, 12:30 and 16:00
Once at the pier
Arrived at the pier you will need to purchase your ferry ticket if you haven't done it at the same time you purchased your bus ticket.
Walk to the ferry when it's ready and enjoy the cruise. Once you arrive in Koh Chang, you can take a taxi which will drive you to your final destination. It will be fully loaded but don't worry, most of the time it succeeds to drive on the narrow roads and crawl on top of the steep hills which by the way are common on the island. Anyway, it can be an adventurous way to start your holidays.
It's also possible to arrange a pick-up with some resorts or hotels. Contact them in advance to ask.