Likelihood of Confusion and Ex Officio Examination: How Thailand’s DIP Blocks Conflicts Before Publication

One of the most distinctive features of Thailand’s trade mark system is its ex officio examination for likelihood of confusion. Unlike jurisdictions where the trade mark office examines only absolute grounds (distinctiveness, descriptiveness) and leaves relative grounds (similarity with prior marks) to be raised by third parties through opposition, Thailand’s Department of Intellectual Property (DIP) proactively examines every application against the register for potential conflicts. Under Section 13 of the Thai Trademark Act, the DIP Registrar must refuse an application that is identical or confusingly similar to an existing registration — before it ever reaches publication. This pre-emptive system has important implications for filing strategy, clearance searches, and the handling of conflicts.

The Legal Framework: Section 13

Section 13 of the Thai Trademark Act, as amended by the Trademark Act (No. 3) B.E. 2559 (2016), provides that the Registrar shall not register a trade mark if:

• Section 13(1): The mark is identical with a trade mark already registered by another person.
• Section 13(2): The mark is so similar to a registered trade mark of another person that the public might be confused or misled as to the ownership or origin of the goods, whether for goods in the same class or in different classes found to be of the same character.

This provision is mandatory: the Registrar “shall not register” the mark. Unlike some jurisdictions that give examiners discretion to weigh similarity factors and allow borderline marks to proceed to publication, the Thai system imposes a duty to refuse when the Registrar finds confusing similarity.

The Ex Officio Nature of the Examination

The critical distinction in Thai practice is that the Section 13 examination is conducted by the DIP examiner on its own initiative, without any action from the prior mark owner. The examiner searches the register and pending applications, compares marks, and issues a refusal if a conflict is found. The prior mark owner need not monitor the Official Gazette, file an opposition, or take any action at all — the DIP acts as a gatekeeper.

This means that in Thailand, most conflicts are resolved before publication, not after. By the time an application is published in the Official Gazette for opposition (under Section 29), the DIP has already cleared it against the register. The 60-day opposition period that follows publication is an additional safeguard, but the primary filter is the examiner’s own search.

Cross-Class Examination

An important feature of Section 13(2) is that the similarity assessment is not limited to goods within the same Nice class. The Registrar must also refuse a mark if the goods are in different classes but are found to be “of the same character.” This means the DIP will examine across classes for goods that share a similar nature, purpose, or consumer channel.

For example, a mark for food products (Class 29) may be cited against a prior mark for restaurant services (Class 43) if the Registrar considers the goods and services to be of the same character. Similarly, cosmetics (Class 3) and pharmaceutical preparations (Class 5) are often treated as related. This cross-class examination creates broader exposure to potential conflicts than applicants accustomed to class-by-class systems might expect.

How the DIP Assesses Similarity

The DIP’s similarity assessment considers the overall impression of the marks, including visual appearance, phonetic similarity, and conceptual meaning. In practice, the DIP tends to focus heavily on visual and phonetic comparison, particularly for word marks. The assessment includes:

• Visual comparison: The overall look of the marks, including design elements, spatial layout, and dominant features.
• Phonetic comparison: How the marks sound when spoken, including in Thai pronunciation. For English-language marks, the DIP considers how Thai consumers would pronounce them.
• Conceptual comparison: The meaning conveyed by each mark, including translations and transliterations into Thai. The DIP will check whether the Thai translation or meaning of a foreign word mark conflicts with an existing registration.

Importantly, when the DIP finds a prior mark, the applicant cannot respond directly to the examiner to argue non-similarity. If the examiner refuses registration on Section 13 grounds, the applicant’s only recourse is to appeal to the Board of Trademarks within 60 days from the notification date. The examiner’s decision is binary — register or refuse — without an intermediate dialogue on relative grounds.

Section 27: The Honest Concurrent Use Exception

The Thai Trademark Act provides one narrow exception to the rigid Section 13 framework. Under Section 27, if the Registrar is satisfied that there has been “honest concurrent use” or that other special circumstances make it proper to do so, the Registrar may allow registration of marks that would otherwise be refused under Section 13 or Section 20 (pending conflicting applications). The registration may be subject to conditions or limitations as to the mode or place of use.

In practice, this exception is rarely invoked. The DIP applies it narrowly, and applicants must provide substantial evidence of concurrent use in Thailand over a significant period. It is not a reliable strategy for most applicants.

The Opposition Process: A Secondary Safety Net

After the DIP clears an application through its ex officio examination and any issues are resolved, the mark is published in the Official Gazette. Third parties then have 60 days to file an opposition. The grounds for opposition include those under Section 13 (confusing similarity), Section 8 (prohibited marks, including well-known marks), and other registrability grounds.

Because the DIP has already screened for obvious conflicts, oppositions in Thailand tend to involve more nuanced cases — marks the examiner cleared but that the prior mark owner considers too close, or conflicts based on well-known mark status that the examiner did not raise. The opposition examiner issues a decision within approximately 12–14 months, with a further appeal available to the Board of Trademarks and ultimately the Central Intellectual Property and International Trade Court (CIPIT Court).

Strategic Recommendations

• Conduct thorough pre-filing searches: Because the DIP examines for relative grounds ex officio, a conflict with a prior mark will surface during examination, not just if the prior owner opposes. A pre-filing search is essential to avoid wasted time and fees.
• Search across related classes: The DIP’s cross-class examination means that a conflict may arise from a registration in a different Nice class. Search beyond your target class to include related goods and services.
• Check Thai translations and transliterations: The DIP considers how foreign marks are perceived in Thai. A mark that appears different in English may create a conflict when transliterated into Thai script.
• Prepare for appeals, not examiner dialogue: Unlike some jurisdictions, there is no informal response mechanism for Section 13 refusals. If refused, the only option is a formal appeal to the Board of Trademarks within 60 days.
• Monitor the Gazette for your own marks: While the DIP examines proactively, it may not catch every conflict, particularly for marks with subtle conceptual or phonetic similarities. Monitor the Official Gazette to catch applications the examiner may have missed.

Common Mistakes

• Assuming similarity issues are raised only by third parties: In Thailand, the DIP raises them on its own. A conflict will block your application even if the prior owner is unaware of your filing.
• Searching only the target Nice class: The DIP’s “same character” standard extends across classes. Limiting searches to a single class creates blind spots.
• Attempting to negotiate with the examiner: Section 13 refusals do not allow for a response or argument to the examiner. The path is an appeal to the Board, not a dialogue with the DIP.
• Underestimating the DIP’s conservatism: The DIP takes a cautious approach to similarity and tends to refuse when in doubt. Borderline marks that might pass in other jurisdictions are more likely to be refused in Thailand.

Key Takeaway

Thailand’s ex officio examination under Section 13 means that the DIP acts as an active gatekeeper against confusingly similar marks, screening applications against the entire register — including across related classes — before publication. For applicants, this front-loaded system places a premium on thorough pre-filing searches and acceptance that most conflicts will be resolved during examination rather than through opposition. For prior mark owners, the system provides an automatic layer of protection, but monitoring remains advisable for subtle conflicts the examiner may not catch.