Dear Mr Chong:
Greeting from Thailand Elite Member Contact Centre…
Further to your mail; please be informed that Korean passport holder does not need the visa for entry Thailand, allows no longer than 90 Days to stay in the Kingdom.
However, depending on the discretion of the immigration officer which quite strict for Korean passport holder.
Also, kindly be reminded that the holder must possess a passport with at least six-month validity and must present full paid of returning ticket which is usable on the date of entry for the purpose of tourism.
We hope the above explanation is useful and we look forward to hearing back from you.
Best Regards,
Manat K.
Thailand Elite Member Contact Center