Thailand’s New E-Commerce Competition Guidelines — What They Mean, What They Miss, and Where the Real Battles Will Be Fought
Law & Economics Insights
April 2026 | Dr Peerapat Chokesuwattanaskul, Praewa Jittimanee, Rinreda Sakiyarak
On 24 March 2026, the Trade Competition Commission of Thailand (“TCCT”) published its first regulatory instrument specifically targeting digital platform conduct. The Notification on Guidelines for Determining Trade Practices that are Unfair, Monopolizing, or Restricting Competition in E-Commerce Multi-sided Platform Businesses (the “Notification”) is a significant moment for Thai competition policy. It signals that the regulator is paying attention to platform economics, has studied the international playbook, and is prepared to act.
But a signal is not the same as a regime. The Notification is not Thailand’s Digital Markets Act. It does not impose prospective obligations on designated gatekeepers. It does not shift the burden of proof to platforms. It does not eliminate the need to prove competitive harm case by case. What it does is map the conduct that the TCCT considers problematic — self-preferencing, rate parity clauses, tying and bundling, data leveraging, platform collusion — and announce, in effect: we know what you are doing, and we now have a framework to pursue it.
Whether that framework works depends entirely on execution — specifically, on the TCCT’s capacity to conduct the sophisticated economic analysis that platform-market enforcement demands. This article argues that the Notification’s real significance lies not in its conduct list, which is broadly aligned with international practice, but in what it reveals about the enforcement economics Thailand must now confront.
Three things every platform operator needs to know
1. This is not Thailand’s DMA. The Notification is an ex post, effects-based instrument. Every case requires proof of anticompetitive effect — which creates both an enforcement challenge for the TCCT and a defence opportunity for platforms.
2. The Section 5 safe harbour is your first line of defence. Conduct with a reasonable economic, business, or technological justification; that follows established industry practice; or that does not significantly affect competition is excluded. Documenting these justifications is now an operational priority.
3. The scope is narrow but the legal tools are broad. The Notification covers e-commerce only, but the underlying TCA provisions (ss.50, 54, 55, 57, 58) carry fines of up to 10% of annual revenue and criminal liability for executives. The Notification tells you what conduct is in the crosshairs — the TCA determines the consequences.
1. What the Notification Does
The Notification is issued under Section 17(3) of the Trade Competition Act B.E. 2560 (“TCA”), which empowers the TCCT to prescribe guidelines for determining prohibited conduct. It covers any operator of a digital e-commerce platform — whether an e-marketplace, social commerce platform, or any other intermediary connecting sellers, logistics providers, advertisers, and payment services.
Two features of its scope deserve attention. First, there is no size threshold. Unlike the EU’s Digital Markets Act, which formally designates “gatekeepers” based on revenue and user-count criteria, the Notification applies in principle to any e-commerce platform operating in Thailand. In practice, however, conduct grounded in abuse of dominance under Section 50 of the TCA can only be pursued against firms holding a dominant market position — a separate factual determination. Second, the Notification is an interpretive guideline, not a standalone regulation. It maps specific platform practices onto existing TCA prohibitions (Sections 50, 54, 55, 57, and 58) rather than creating new ones.
The Conduct Taxonomy
The Notification’s conduct list under Clause 4 is comprehensive and broadly familiar to anyone who has followed EU or US platform regulation debates. The commercially significant categories fall into three groups.
Pricing conduct covers rate parity clauses (requiring sellers to match or not undercut prices across platforms), resale price maintenance, predatory pricing below average total cost, and excessive or unjustified fees — including commission, logistics, and advertising charges set at disproportionate rates without reasonable justification. The rate parity provision is particularly noteworthy: it includes a narrow exception for genuine intellectual property licensing arrangements, but standard seller agreements will not qualify.
Non-price exclusionary conduct includes self-preferencing (using algorithms to boost the platform’s own products or favoured sellers without disclosure), mandatory use of platform logistics or payment services, exclusive dealing (prohibiting sellers from listing on competing platforms), tying and bundling (conditioning access on purchasing additional services), and anti-competitive use of third-party data to create barriers to entry.
Coordination covers collusion between competing platforms or between a platform and its business users, including keyword-bidding collusion and concerted practices — whether express or implied, binding or non-binding.
The Section 5 Defence
The Notification’s most consequential feature may be its exception framework under Clause 5. Conduct will not be deemed unfair or unreasonable if it satisfies any of three conditions: (1) it has a reasonable economic, business, or technological justification; (2) it is consistent with established industry practice or trade custom; or (3) it does not significantly affect competition. These defences are broad, and they will be the primary battleground in any enforcement action.
2. Not a DMA — And That Matters
The comparison with the EU’s Digital Markets Act is inevitable, but the structural differences are fundamental and have direct consequences for compliance planning, enforcement timelines, and litigation strategy.
The DMA is an ex ante regulatory instrument. Once a firm is designated as a gatekeeper, it must comply with specified obligations prospectively — without any requirement for the European Commission to demonstrate that specific conduct caused harm. The Notification operates in the opposite direction: it is an ex post, effects-based instrument. The TCCT must investigate each case, define the relevant market, assess competitive effects, and consider applicable defences before reaching a determination. This is traditional competition enforcement wearing a platform-specific taxonomy.
Dimension | TCCT Notification | EU Digital Markets Act
Legal nature | Interpretive guideline under the TCA | Self-standing ex ante regulation
Enforcement model | Ex post, effects-based, case-by-case | Ex ante, per se obligations on gatekeepers
Burden of proof | Authority must demonstrate anticompetitive effect | Gatekeeper must comply upon designation
Scope | E-commerce platforms (as defined) | 10 categories of core platform services
Designation | No formal designation; dominance must be established for Section 50 claims | Formal gatekeeper designation based on quantitative thresholds
Defences | Three-part exception (Clause 5): justification, industry practice, no significant effect | Limited: Article 9 suspension, Article 10 exemption (health/security only)
Several categories of conduct appear in one instrument but not the other. The Notification addresses excessive and predatory pricing, standalone collusion provisions, and price discrimination between sellers — none of which the DMA covers directly. Conversely, the DMA addresses data portability and interoperability, side-loading and alternative app stores, cross-service personal data combination with consent requirements, and detailed advertising transparency and data access obligations — none of which the Notification touches.
The practical implication is straightforward: platforms operating in both jurisdictions face overlapping but distinct compliance requirements. A DMA compliance programme will not satisfy Thai requirements, and vice versa.
3. The Real Challenge: Enforcement Economics
The Notification’s conduct list is sophisticated, but lists do not enforce themselves. The quality of economic analysis — by both the regulator and the platforms — will determine whether this framework has any teeth.
Because the Notification operates within the TCA’s ex post enforcement model, every case will require the TCCT to define the relevant market, establish competitive effects, and overcome the Section 5 defences. Each of these steps demands substantial economic analysis. This is where platform-specific economics create the most significant challenges for enforcement — and the most significant opportunities for platforms to contest findings.
Market Definition in Two-Sided Markets
E-commerce platforms serve at least two distinct groups simultaneously. Pricing on one side may be zero (buyers pay nothing to browse) while the platform recovers revenue from the other (sellers pay commission). Applying a standard SSNIP test to one side in isolation produces distorted results. The question of whether a multi-sided platform constitutes a single market or multiple interrelated markets remains unsettled internationally. The US Supreme Court in Ohio v. American Express Co. (2018) adopted a unified market approach for transaction platforms, requiring competitive effects to be assessed across both sides simultaneously. The EU has generally preferred to define separate but interrelated markets in cases such as Mastercard v. Commission and Google Shopping. Thai competition law has not yet articulated a position on this question — and the TCCT’s choice of approach will materially affect market share calculations, dominance findings, and the outcome of every case brought under the Notification.
Economic Tests by Conduct
Each category of prohibited conduct engages different economic methodologies, evidentiary standards, and data requirements. The table below maps the key conducts to their applicable TCA provisions and the economic analysis that both prosecution and defence will need to deploy.
Conduct | TCA Provision | Economic Test | Key Data
Predatory pricing | ss.50 + 54 | AAC / LRAIC cost test; recoupment analysis | Cost breakdowns by platform side; cross-subsidy flows
Excessive fees | ss.50 + 54 | Economic value test; cost-plus benchmark; regional comparators | Fee schedules across regional platforms; cost-of-service data
Rate parity / MFN | s.57 | Price dispersion across channels; counterfactual absent parity | Price listings across platforms; multi-homing data
Self-preferencing | ss.50 + 54 | Ranking audit; A/B algorithm testing; CTR analysis | Algorithm parameters; search logs; seller performance metrics
Tying & bundling | s.57 | Separate-product test; downstream foreclosure analysis | Seller opt-out rates; logistics market share; alternative usage
Data leveraging | ss.50+54 or 57 | Competitive advantage from data; causal link to foreclosure | Data inventories; downstream metrics; comparator firms
Platform collusion | ss.55 or 58 | Plus-factors analysis; information exchange evidence | Bidding data; fee-change timing; internal communications
The Section 5 Defence in Practice
From an enforcement perspective, the breadth of the Section 5 defences is the Notification’s most significant structural vulnerability. The “reasonable justification” limb is the strongest and most principled: a platform that demonstrates with data and expert analysis that its conduct increases efficiency or improves consumer welfare will generally prevail. The “established industry practice” limb is the most dangerous from a regulatory integrity standpoint — if a practice is near-universal precisely because all major platforms adopted it, the defence risks swallowing the prohibition entirely. The “no significant competitive effect” limb requires quantitative analysis, but the Notification provides no guidance on what threshold constitutes “significant,” which is a material gap that will need to be filled by case law or supplementary guidance.
Enforcement Realism
The TCCT’s capacity to conduct the sophisticated economic analysis required for platform-market enforcement is still developing. In the near term, enforcement is most likely to focus on cases where the competitive harm is relatively visible and documentable — an explicit rate parity clause with clear price effects, a documented case of account suspension as retaliation for multi-homing, a transparent instance of mandatory logistics bundling. The platform involved will likely hold clear market dominance, and there will be a well-organised complainant able to provide structured evidence.
More complex cases — data leveraging, algorithmic self-preferencing, tacit collusion — will require greater investigation capacity and economic expertise. Platforms operating in these areas have a longer runway before enforcement becomes a realistic near-term risk, but the regulatory direction is unambiguous.
4. What To Do Now
The Notification is not a cause for alarm, but it is a clear directive. Every participant in the Thai e-commerce ecosystem needs to understand their exposure.
Platform operators bear the broadest exposure. Rate parity clauses in seller agreements, mandatory use of platform logistics, self-preferencing in search and ranking algorithms, tying advertising to platform access, and compulsory participation in promotional events are all now explicitly flagged as potentially unlawful. The compliance priority is a structured audit of all seller agreement terms, algorithmic ranking policies, fee structures, and promotional mechanics — with a documented Section 5 justification for each practice that touches Clause 4, prepared now, before an investigation rather than during one.
Sellers are primarily beneficiaries of the Notification’s protections, but they are also directly subject to TCA provisions where their own conduct is at issue. Sellers bound by rate parity clauses may now have grounds to challenge them; sellers experiencing informal or formal pressure not to list on competing platforms should document those pressures carefully. And sellers who participate in or facilitate keyword-bidding coordination face potential co-respondent liability under the collusion provisions.
Logistics providers and payment services have narrower but real exposure. Platforms that set their own logistics arm as the default carrier with no practical alternative, or that mandate the use of their own payment service while blocking third-party providers, are now in scope. Given the rapid growth of payment platform revenues as a share of e-commerce economics, this provision is likely to receive increasing enforcement attention.
For all participants, the most important near-term action is to invest in economic analysis of your relevant market position. Multi-homing rates, market share calculations, and market definition will be the first battlefield in any investigation. Platforms and market participants that have done this work proactively will be substantially better positioned than those scrambling to commission it after receiving a complaint notification.
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This article is prepared for informational purposes and does not constitute legal advice. Readers should seek specific legal and economic counsel in relation to their individual circumstances.
About VA Partners
VA Partners stands at the intersection of law, economics, and strategy, offering industry-leading advisory services for complex matters including competition law, merger review, damages valuation, public policy design, and platform regulation across Asia Pacific. The firm combines deep econometric credibility with established regulatory relationships — including repeat advisory engagements with the Trade Competition Commission of Thailand, the ASEAN Secretariat, and the OECD — to deliver rigorous, evidence-based analysis that carries weight in proceedings. For platform operators and market participants navigating the new e-commerce competition landscape, VA Partners provides the economic analysis, expert testimony, and compliance advisory that this framework demands.