E-commerce platforms connect many parties at once, and their control of user data and algorithms gives them market power that can be used to monopolise or restrict competition. Against this backdrop, the Trade Competition Commission of Thailand (the "TCCT") issued the Notification Re: Guidelines on Unfair Trade Practices, Monopolisation and Acts Restricting or Reducing Competition in Multi-Sided Platform Businesses, Type: E-Commerce Digital Platform Businesses (the "Guidelines"), which came into effect on 25 March 2026. The Guidelines were introduced to address increasing concerns regarding the growing influence of digital platforms, particularly in relation to platform self-preferencing, algorithm-driven conduct, unfair treatment of counterparties, and the ability for dominant platforms to distort competition within Thailand’s rapidly expanding digital economy.

The Guidelines set out a conduct-specific framework for e-commerce platforms under the Trade Competition Act B.E. 2560 (the “TCA”), covering abuse of market power, horizontal restraints, other anti-competitive agreements, unfair trade practices, and cross-border arrangements by Thai operators with foreign counterparts that monopolise or unfairly restrict trade in Thailand.

Scope

The Guidelines apply to operators of e-commerce platforms, which are intermediaries facilitating the sale, purchase or exchange of goods or services through an electronic transaction system, in any form (e-marketplace, social-marketplace or otherwise), whether or not a service fee is charged.

The Guidelines mainly regulate platforms’ conduct toward four counterparty groups:

Sellers: distributors, manufacturers, importers, resellers and service providers using the platform to offer goods or services;

Carriers: logistics providers engaged through the platform to handle pickup and delivery;

Digital media advertisers: providers of advertising and promotional services on the platform; and

Payment channels: online payment service providers.

Fair Conduct and Prohibited Practices

According to the Guidelines, e-commerce platform operators must deal fairly with each of the four counterparty groups, consistent with the TCA. The Guidelines also identify the following categories of conduct that may be considered monopolising, reducing or restricting competition.

Price behaviours:

  • requiring sellers to set sale prices below their total average cost;
  • requiring sellers to charge the same price across all channels, or barring them from offering lower prices on competing platforms, except where this is part of a genuine intellectual property licensing arrangement or an agreement or business form prescribed by other applicable laws;
  • dictating the resale price of goods or services, and enforcing this by refusing to deal with sellers who do not comply;
  • charging commission, advertising, logistics, promotion or payment fees that lack reasonable justification, for example, fees that are excessive against past rates, fees set in parallel with competitors, fees charged below cost (predatory pricing), fees applied discriminatorily without justification, or fees changed without adequate prior notice; and
  • any other conduct, direct or indirect, that distorts the price of goods or services unfairly, including algorithmic systems that set or rank prices without reasonable cause.

Non-price behaviours:

  • using algorithms to bury sellers' listings, or to push the platform's own goods or those of affiliated sellers to the front, including through paid placement that is not disclosed as advertising;
  • requiring sellers to use the platform’s own logistics, payment or advertising services, or compelling them to take part in long-running promotional campaigns (e.g. double-date campaigns);
  • preventing counterparties from offering their goods on competing platforms, with non-compliance punished by suspending accounts, delisting products or refusing to deal, or indirectly through tying of platform services, anti-competitive use of third-party data, or restricting logistics to platform-affiliated carriers;
  • treating similar sellers differently without good reason, for instance by ranking their listings differently, or steering more orders to the platform's own carriers than to third-party ones;
  • favouring the platform's own affiliated businesses, including by using data collected on the platform to give them a competitive edge, or by granting its own services preferences not available to counterparties;
  • coordinating with competing platforms or among counterparties, including by colluding on keyword auctions; and
  • any other conduct that monopolises or restricts competition, such as delaying payment to counterparties, or changing commercial terms without giving reasonable notice.

Exceptions

Conduct otherwise falling within the categories above will not be treated as unfair or without reasonable cause if any one of the following is satisfied:

  • it has a reasonable economic, business or technological basis;
  • it is consistent with prevailing trade custom, or with conduct that similarly-situated operators may undertake to foster or maintain competition; or
  • it does not materially affect overall market competition, does not unduly restrict, distort or exclude competition, and does not impose an unfair burden on other operators.

The TCCT may also take into account other relevant factors, including the nature of the contractual relationship and other applicable legal constraints.

Practical Considerations for E-Commerce Platform Operators

Given the scope of the Guidelines, e-commerce platform operators should proactively review their commercial arrangements and operational practices to mitigate potential competition risks. In particular, operators may wish to consider:

  • reviewing pricing parity clauses, exclusivity arrangements and mandatory service bundling requirements;
  • assessing whether platform ranking algorithms or recommendation systems could be perceived as unfairly favouring affiliated businesses or the platform’s own products or services;
  • ensuring that sponsored placement and paid promotional rankings are clearly disclosed to users; and
  • maintaining clear internal documentation supporting the economic or technological justification for potentially restrictive conduct.

Conclusion

The Guidelines signal the TCCT’s increasing focus on competition concerns arising from the growing influence of digital platform businesses in Thailand. Non-compliance with the Guidelines may expose platform operators to investigation and enforcement action by the TCCT under the TCA, including administrative fines, criminal penalties, and reputational risks arising from increased regulatory scrutiny. As Thailand’s digital economy continues to expand, the Guidelines will likely play an increasingly important role in shaping acceptable market conduct.

This update is intended solely to provide general information on recent regulatory and enforcement developments in Thailand and does not constitute legal advice or a legal opinion. Specific legal advice should be sought in relation to individual circumstances.