I am going to Bangkok and I plan on using the Skytrain. How do I purchase tickets?
Reply from Thailand Info
You need to use the ticket machines as pictured below which are located before the barriers in every BTS (Skytrain) station.
The machines are coin operated. What you need to do is to look at the station map beside the machine. Beside each station an amount in Thai baht is given. Once you know the amount you press the button for that amount on the machine and insert coins up to that value.
The machines give change but do not accept notes. You can change notes at the glass kiosks which are located by the barriers. When you have inserted the right amount a ticket will drop out of the bottom of the machine and you ready to take your journey.