The VISA ON ARRIVAL allows passport holders of 19* countries to enter Thailand under this rule provided that they meet these requirements:
The visit is strictly for tourism purposes.
The passport must be genuine and should be valid for at least 30 days.
You must have a valid address in Thailand whether a hotel or apartment that can be verified.
You must have a confirmed return ticket to show that they are flying out of Thailand within 15 days of entry, as appropriate. Open tickets do not qualify. Travelling overland out of Thailand by train, bus, etc to Cambodia, Laos, Malaysia (including en route to Singapore), Myanmar, etc is not accepted as proof of exiting Thailand.
You may be asked to show your flight ticket on entering Thailand. If you do not possess a flight ticket to show that you will be exiting Thailand within 15 days of entry you will be most likely refused entry.
It will also be necessary to prove that you have funds of at least 10,000 THB per person and 20,000 THB per family during your stay in Thailand.
A fee of 2,000 THB is payable upon entry and is subject to change without notice. It must be paid in cash and Thai currency only.
However, persons who are not eligible to enter Thailand under the VISA ON ARRIVAL and VISA EXEMPTION RULE are advised to obtain visas with the Royal Thai Embassy prior to their visit.
* List of countries eligible for the Visa on Arrival:
Papua New Guinea
List of Thailand’s Immigration Checkpoints which provide facilities for issuance of visa on arrival:
Don Muang International Airport, Bangkok
Chiangmai International Airport, Chiangmai
Phuket International Airport, Phuket
Hatyai International Airport, Songkhla
U Tapao Airport, Rayong
Mae Sai Immigration Checkpoint, Chiengrai
Chieng Saen Immigration Checkpoint, Chiengrai
Chieng Khong Immigration Checkpoint, Chiengrai
Betong Immigration Checkpoint, Yala
Sadoa Immigration Checkpoint, Songkhla
Samui Airport, Surat Thani
Sukhothai International Airport, Tak Immigration Checkpoint