When do I require a Work Permit?
Any foreigner working in Thailand must have a work permit, and the definition of work is extremely broad. Work is defined as "engaging in work by exerting energy or using knowledge whether or not in consideration of wages or other benefits." Many foreigners find this broad definition of work counterintuitive because it can encompass such short-term activities as participating in a single business meeting.
Is a business visa sufficient if I am only speaking at or attending a business meeting?
No. Foreigners often confuse non-immigrant "B" (business) visas with work permits and believe such visas grant them the right to engage in work on a short time basis in Thailand. They do not.
But the Thai Office of Council of State – an advisory group on legal matters for the executive branch – has advised the Department of Employment that an attendee at a conference, exhibition, etc. not exceeding 15 days does not require a work permit. See here for more details on the guidelines implemented by the Department of Employment as a result of the Office of Council of State’s advice.
Who issues Work Permits?
Work permits can only be granted by the Alien Occupation Division of the Employment Department, Ministry of Labour ("Alien Occupation Division").
In other countries a business visa is sufficient when I am simply attending a business meeting. Why can't I obtain a business visa or some other approval to attend a business meeting from a Thai Embassy while outside of Thailand?
Thai embassies and consulates cannot grant work permits. In Thailand, separate Ministries are responsible for issuing (a) visas and other approvals to stay in Thailand and (b) work permits. The Alien Occupation Division is the only agency that can issue work permits, and they do not have offices outside of Thailand to process and issue work permits. Thai Embassies can issue business visas, but business visas do not allow foreigners to work in Thailand.
Are foreigners working in Thailand without a work permit ever arrested?
Yes. Arrests for work permit violations are not common, but they do occur.
What could happen if I am arrested?
The penalty for working without a work permit includes imprisonment of up to five years or a fine of not exceeding 100,000 Baht or both. Under the Work Permit Act, B.E. 2551, an official may only impose a fine with deportation. In practice, a brief detention and deportation are more likely, but there is also the embarrassment and risk of adverse publicity associated with a work permit arrest.
So how do I comply with this law if I am simply coming into Thailand for several days of "work"?
A foreigner can obtain an "urgent work permit" valid for up to 15 days to perform certain types of work, including attending business meetings, conducting an inspection or performing internal audit work. A work permit of this type can usually be obtained within a day of arrival in the country. No particular type of entry visa is required.