Foreigners entering Thailand must obtain a visa that matches the purpose of entering the country. However, visa approval is at the discretion of the Consulate General. 

Foreigners traveling through the territory of Thailand to make their way to a third country may have to apply for a Thailand transit visa. The categories of transit visas are as follows:  

• Category “TS” is issued to foreigners transiting through the territory of Thailand on their way to a third destination;
• Category “S” is issued to foreign sports persons entering Thailand to participate in sporting events;
• Category “C” is issued to crew members of a conveyance that is coming to a port, station, or other location in Thailand. 

    A transit visa is valid for 3 months with a maximum allowed stay up to 30 days per entry. The transit visa fee is 800 baht and proof of sufficient funds to cover the duration of the stay must be shown: 10,000 baht if traveling alone or 20,000 baht if traveling as a family.

Supporting documents required are the following:

• Passport or travel document with a minimum of 6 months validity;
• A completed and signed Thailand transit visa application form;
• Two 2½-inc photos taken within the past 6 months, with no hat and no sunglasses;
• Confirmed travel ticket to a third country;
• Proof of onward travel within a certain period of time after finishing traveling in Thailand:
  • For a TS category visa, passport or travel document is required;
  • For an S category visa, a letter of invitation stating the applicant’s participation is required;
  • For a C category visa, a letter of confirmation from the applicant’s employer, stating the purpose of entering Thailand, is required. 
• The applicant may be asked to submit additional documents or may be interviewed, as per the request of the Embassy or Consulate.

Source : Ministry of Foreign Affairs
Tel : +66 2203-5000