In its 2025 Peer Reviews of Competition Law and Policy: Thailand, the Organization for Economic Co-operation and Development (OECD) delivered a comprehensive assessment of Thailand’s competition framework, praising significant strides towards international best practices while identifying structural weaknesses and under-enforcement that continue to limit its effectiveness. The review underscores Thailand’s transition to a modern, EU- and U.S.-inspired regime under the Trade Competition Act B.E. 2560 (2017), but also calls for greater institutional capacity, transparency, and clearer legal standards.
A Modernized Legal Framework, Hampered by Ambiguities
The 2017 Act replaced the outdated 1999 law, introducing an independent enforcement authority, a formal merger control regime, a leniency program for cartel reporting, and provisions to address abuse of dominance. It combines per se prohibitions with rule-of-reason analysis, reflecting a balanced approach to enforcement. Importantly, it created the Trade Competition Commission (TCC), vested with decision-making powers, and the Office of the Trade Competition Commission (OTCC), tasked with investigations and administration. The separation from the Ministry of Commerce was designed to insulate enforcement from political influence.
However, despite these structural advances, key concepts such as “market dominance” and “substantial lessening of competition” remain vaguely defined, leading to inconsistent application. The OECD also notes that enforcement activity has been modest, raising questions about the regime’s deterrent effect.
Enforcement Capacity and Institutional Constraints
The OTCC is equipped with investigative tools, including dawn raids, compulsory information requests, and the ability to cooperate with public prosecutors. Yet its work is constrained by limited funding, insufficient specialist expertise, and staff shortages. Reliance on public prosecutors for criminal proceedings often results in delays, and penalties—although potentially severe—are rarely applied.
The OECD also observes a lack of detailed guidance for businesses, minimal precedent-setting decisions, and an absence of safe harbor thresholds or modern analytical tools to address challenges such as algorithmic collusion in digital markets.
Substantive Provisions and Practical Gaps
The Act prohibits horizontal agreements such as price fixing, bid rigging, and market allocation, as well as certain vertical restraints that may harm competition. It also outlaws abuses of dominance, including predatory pricing, refusal to deal, and unfair contractual terms, with dominance presumed for firms holding over 50% market share and annual turnover exceeding THB 1 billion. In practice, however, dominance assessments have not yet been adapted to the realities of digital and network-based markets.
Merger control operates on a dual-track system: ex-ante approval is required for transactions likely to create a monopoly or dominance, while ex-post notification is mandated for mergers meeting certain revenue thresholds. The OECD finds this structure unnecessarily complex and recommends replacing it with a single, more robust regime that would allow the TCC to block problematic transactions. Procedural transparency is another concern, as illustrated by the CP–Tesco merger review, where public disclosure was limited and analytical reasoning insufficient.
Procedural and Transparency Shortcomings
While the Act provides for interim measures to prevent imminent harm to competition, these have never been used due to procedural uncertainty. Settlement mechanisms exist in criminal cases but lack clear discount guidelines and transparency, and are unavailable for administrative cases. The TCC publishes only anonymized summaries of its decisions, omitting detailed reasoning, the identities of sanctioned parties, and the methodology for calculating penalties. The OECD warns that such opacity undermines legal certainty and public trust.
Private enforcement remains purely theoretical, with no cases filed to date. The short statute of limitations, the absence of public decisions to support follow-on claims, and restricted access to case files have made this route effectively inaccessible.
OECD’s Reform Recommendations
The OECD’s recommendations are phased, with immediate priorities including increased budget and staffing for the OTCC, clearer legal definitions, more transparent publication of decisions, and the development of sanction guidelines. It also urges more proactive action against cartels, modernized dominance tests, streamlined merger control, and stronger advocacy powers for the TCC.
Longer-term measures focus on equipping the OTCC with market screening and data analytics tools, enhancing leniency and settlement procedures, allowing commitment-based case closures, and institutionalizing both domestic and international enforcement cooperation.
Strategic Takeaways
The OECD’s 2025 review confirms that Thailand has laid a solid foundation for an effective competition regime, but also makes clear that the law’s potential remains under-realized. Strengthening institutional capacity, clarifying substantive rules, improving procedural transparency, and modernizing enforcement tools will be critical to achieving the deterrent effect and market confidence that a mature competition framework demands.
For businesses active in Thailand, these developments signal the likelihood of more assertive and sophisticated enforcement in the years ahead. Proactive compliance and early engagement with regulators will be essential to navigating this evolving landscape.
For tailored legal advice on Thailand’s competition law and regulatory compliance, contact Mahanakorn Partners Group at [email protected].