Over night train tickets
Hi, sure. Dont worry its very easy. The sleeper train goes from Bangkok Haulampong straight through to Chiang Mai. You just turn up at the station and buy your tickets there and then. You can go and buy them the day before if you are worried about getting them but it generally isnt a problem unless you are travelling during a major holiday. Enjoy your trip!
You can check out the timetables and fares here www.thairailticket.com/esrt/Default.a...
There has been an on/ off possibility to buy tickets online – seems it’s off at the moment. As Michael said, it’s easy to buy tickets at the station, or any tour/ticket agency near your accommodation in Bangkok should be able to book them for you.
Second class sleeper is a great way to travel, by the way.
Although this question was asked a while ago – I used this website to buy tickets online -
They will deliver to your accommodation in Bangkok free of charge, or for a fee (300 baht), will bring them to Hua Lamphong station about an hour before your train is due to depart.
Second class is fine and if you are wanting a sleeper, I would advise pre-booking. You can also purchase the tickets from other stations in Thailand as well.