2542 (1999), first established the body as a bureau under the Ministry of Commerce's Department of Internal Trade, operating as a government agency overseen by an appointed Trade Competition Board (TCB) chaired ex officio by the commerce minister.
Over the following decade, this legal structure proved inefficient and inadequate—the TCB pursued only one case, against A.P.
Honda in 2003, which was dropped after the statute of limitations expired as the case was drawn out for ten years—leading the TCB to be widely seen as a paper tiger.
2560 (2017), repealed the old structure and re-established the OTCC as an independent regulatory agency with broader powers, including the authority to impose fines and penalties and to approve or reject proposed mergers that could lead to "a monopoly or undue market dominance against consumer interests".
[1][2][3] The first high-profile case to come before the new TCC was the sale of the Tesco Lotus hypermarket chain to CP Group in 2020, which was seen as a major test of the agency's will to take on Thailand's powerful business tycoons.