Although the “passing off” principle has sometimes faced criticism for potentially broadening trademark protection—particularly in cases involving unregistered or unconventional marks like shapes, scents, or sounds—it serves an essential purpose. It safeguards the rights of business owners and shields consumers from deception, ensuring fair competition and reflecting the realities of modern commerce. What is passing off, and why is registrability not required? The passing-off principle is a legal concept rooted in English law, aimed at preventing a person from falsely representing or using a mark similar to another’s in a way that causes consumers to mistakenly believe the goods or services come from the same source. Under Thai law, the passing-off principle is provided under Section 46 of the Thai Trademark Act, which states: No person shall be entitled to bring legal proceedings to prevent or to recover damages for the infringement of an unregistered trademark. The provisions of this Section shall not affect the right of the owner of an unregistered trademark to bring legal proceedings against any person for passing off goods as those of the owner of the trademark. The passing-off principle can be interpreted as a practical legal concept. It does not require proof that the mark is registrable or meets the registrability criteria under trademark law. It is sufficient to show that the mark has established goodwill and that the other party’s use of a similar mark is likely to confuse consumers, making it a straightforward and effective tool for protecting brand assets. Requiring a claimant to prove that an unregistered mark could have been registered would undermine the very function of passing off. The doctrine was conceived precisely to fill the gaps left by the registration system. Imposing registrability criteria would nullify its function and leave many commercially valuable identifiers unprotected. If the

Attorneys from Tilleke & Gibbins have updated the latest edition of Doing Business in Thailand, a Q&A-style guide from Thomson Reuters Practical Law that offers an overview of key legal considerations for companies operating in jurisdictions worldwide. The contribution outlines the country’s legal and regulatory framework for foreign investment and business operations and reflects the latest legislative developments. The chapter addresses the following core topics: Legal system: Structure of the courts and the codified nature of Thai law. Foreign investment: Business restrictions under the Foreign Business Act, sector-specific regulations, exchange control rules, and investment incentives. Business vehicles: Overview of partnerships, private and public limited companies, and other legal entities. Employment: Labor protections, employment contracts, foreign worker requirements, and termination procedures. Tax: Corporate and personal income tax, indirect taxes, and tax obligations for residents and non-residents. Intellectual property: Registration and enforcement of patents, trademarks, designs, and copyrights. Data protection: Key provisions of the Personal Data Protection Act and related compliance obligations. Competition law: Regulatory framework under the Trade Competition Act. Anti-bribery and corruption: Relevant legislation and enforcement mechanisms. E-commerce and digital business: Legal regime for online transactions and digital platforms. Marketing and advertising: Consumer protection laws and regulations affecting advertising and marketing practices. Product regulation and liability: Safety standards, liability regimes, and roles of enforcement authorities. Practical Law, a legal reference resource from Thomson Reuters, publishes a range of guides for hundreds of jurisdictions and practice areas. The insurance and reinsurance guide is a valuable resource for legal practitioners, covering numerous jurisdictions worldwide. To view the latest version of the guide, please visit the Practical Law website and enroll in the free Practical Law trial to gain full access.