If your citizenship does not qualify you for a Thailand visa waiver or if you are planning to stay in Thailand for longer than 15/30 days, you must apply for a Thai visa at an embassy or consulate outside of the Kingdom.  Thai tourist visas are valid for 30 or 60 days, though visitors who plan to travel from Thailand to a neighboring country and then back to Thailand can apply for several consecutive 30 or 60 day Thai visas.  At most, three Thai visas can be issued at one time, granting visitors either 30 or 60 days for each entry into Thailand (maximum 3x60 days, requiring visitors to leave within 60 days before beginning the next 60 day visa)

The penalty for overstaying your visa is typically 500 Baht per day, with a 20,000 Baht limit.   Fines can be paid upon departure at the airport.   If you've only overstayed one day, you may not have to pay any fine or you may have to pay 1,000 Baht, depending on the current regulations.  Children less than 14 years old who are traveling with a parent or guardian are not required to pay any fines for overstays.

You can avoid paying any overstay fines by visiting a Thai immigration office and requesting a Thai visa extension.
- The Bangkok immigration office near Sathorn Road,  Soi Suan Phlu,
Tel. 02-287-3101; 09 am -12pm /13:00 -16.30 Mon-Fri, 09 am-12 pm Sat.
- The Chiang Mai immigration office will also provide Thai visa extensions.
Tel. 05-320-1755-6; Th Mahidon; 08.30 am-16.30 pm Mon-Fri). The usual fee for a Thai visa extension is around 2,000 Baht.  Because the immigration offices can be very busy, getting a Thai visa extension may not be practical unless you believe you will overstay your Thai visa by more than 3 or 4 days.  The length of the visa extension depends on the length of your prior Thai visa; typically 7 days extension for a 30 day visa waiver and up to 30 days extension for a 60 day visa.

Other Thai visas, such as non-immigrant, retirement, and student visas should be inquired about at your nearest embassy or consulate, or the Thai Ministry of Foreign Affairs at www.mfa.go.th.

Information on locations and contact numbers of Thailand Embassies and Consulate-Generals abroad may be obtained from the Ministry of Foreign Affairs, Department of Consular Affairs, Visas and Travel Documents Division, 123 Chaeng wattana Road, Bangkok 10210, Tel. (662) 981-7171 ext. 3201-2, 3204-5 or direct line 575-1062-4, Fax. (662) 575-1066 , E-mail : div1303@mfa.go.th

This visa is specially designed for people who want to do business legally in Thailand.   It is also known as Non-Immigrant Business Visa.  You can get a work permit, open a bank account however you still need to do a visa run every 90 days.