The Treaty of Amity and Economic Relations between the Kingdom of Thailand and the United States of America was signed on 29 May 1966. It affords American citizens and US-registered entities a uniquely privileged status under Thai commercial law: the right to establish and operate businesses in Thailand on terms no less favourable than those accorded to Thai nationals.
In practical terms, this means that a qualifying US Treaty of Amity company may hold majority or full ownership of a Thai limited company and conduct business across most sectors — without the need to obtain a Foreign Business License and without being subject to the Foreign Business Act's general prohibition on majority foreign ownership.
For American entrepreneurs, executives, and corporations, the Treaty of Amity represents the most commercially advantageous and legally secure path to establishing a business presence in Thailand.