TIMATIC 에 있는 태국인의 한국 입국에 관련된 규정 올려드리니깐
참고하셔여...

내용을 훼손하지 않기 위해 원문 그대로 옮겼으니 양해를...^-^;;;

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NATIONAL THAILAND (TH)          /EMBARKATION THAILAND (TH)
DESTINATION KOREA (REPUBLIC) (KR)

VISA DESTINATION KOREA (REPUBLIC) (KR)

...... NORMAL PASSPORTS ONLY ......
PASSPORT REQUIRED, OR
CERTIFICATE OF IDENTITY WITH PERMISSION FROM THE MINISTRY OF
JUSTICE OF KOREA (REP.).

VISA NOT REQUIRED FOR A STAY OF MAX. 3 MONTHS.

NON-COMPLIANCE WITH THE ENTRY REGULATIONS WILL RESULT IN FINES
FOR THE AIRLINE AND DEPORTATION OF PASSENGER.

IN ALL CASES:
1. VISITOR MUST HOLD:
  - RETURN/ONWARD TICKET (IF NOT ADVISED OTHERWISE) AND ALL
    DOCUMENTS REQUIRED FOR NEXT DESTINATION; AND
  - SUFFICIENT FUNDS FOR MAINTENANCE; AND
  - CONTACT ADDRESS IN KOREA REP.
2. IF THE PASSENGER HOLDS AN APEC BUSINESS TRAVEL CARD: VISA
  NOT REQUIRED PROVIDED THE BACK OF THE CARD STATES IT
  IS VALID FOR TRAVEL TO KOREA (REP.).