You are using an outdated browser and your browsing experience will not be optimal. Please update to the latest version of Microsoft Edge, Google Chrome or Mozilla Firefox. Install Microsoft Edge

June 2, 2023

Customs Post-assessment Dispute Mechanisms: Challenging Official Duty Assessments

Efficiency and predictability in the global supply chain are critical for business operations. Whether involved in manufacturing, distribution, logistics, or even in the provision of services, most business operators rely upon problem-free customs clearance in the countries in which they operate. If customs disputes do arise and are not effectively addressed, they can have a profound impact on operations, delaying delivery, creating potential civil and criminal liabilities, or even resulting in the seizure of imported goods.

Often, importers or their agents can become complacent, particularly where there has been a period of months or even years of customs clearance without encountering any issues. However, disputes can arise, often relating to origin of goods, classification, and duty assessment. When not addressed early in the dispute process or through settlement, a dispute can escalate, leading to issuance of official letters of assessment by customs authorities. Once Thai customs has issued such a formal letter of assessment to an importer, discretion in settlement is gone and only the full value of the duty assessment can be accepted. At this stage, the only legal avenue for challenge is to accept the duty assessment or to litigate. This article addresses post-assessment litigation options to challenge official customs duty assessments.

Customs Board of Appeals

Once an official assessment is made, an importer has the right to seek a formal appeal of the customs assessment with the Customs Board of Appeals or to otherwise make payment of the full assessment within 30 days of the date it received the assessment. Extensions of time are not permitted. With few exceptions, the right to appeal does not allow the importer to defer an assessed duty payment. This means that the importer must post security for the assessed duty at the time of filing the appeal.

This essentially means that an importer has a tight timeframe in which to prepare and file an appeal and security. Since many customs disputes involve complex issues of goods classification, application of rules of origin, and exemptions under free trade agreements, it is imperative the importers and counsel work in advance of formal assessment so that they are prepared to file appeals within the 30 day period.

The Thai Customs Act provides that the Board of Appeals has 180 days to complete the appellate procedure. The Board of Appeals has the opportunity to extend the procedure for up to 90 days, but only if there is necessary cause. Thereafter, if the appellate procedure cannot be completed within the original or extended time period, an importer has the right to consider withdrawing the appeal and filing a lawsuit in the applicable court.

The Board of Appeals and its Appeal Committee have the right to appoint a subcommittee to perform any entrusted duty. The committee or subcommittee can issue a summons to the appellant or request any person to give an oral statement or submit any documentation concerning the appeal. A Customs Board of Appeals ruling is final, made in writing, and submitted to the appellant. If the appellant is dissatisfied with the ruling, it has the right to file a lawsuit in court within thirty days of receiving the ruling.

Filing Claims with the Court

Where there has been an official duty assessment by Thai customs, an importer, if it wishes to bypass the Customs Board of Appeals process, has the right to file a direct claim with the court of jurisdiction for a customs dispute. This is typically the specialized Tax Court. Alternatively, an importer can await the conclusion of the Customs Board of Appeals process before exercising its right to file a claim with the applicable court. This is a decision that each importer needs to consider on its own, but in most cases the initial decision will be to file appeals with the Board of Appeals as a first dispute resolution option, and only if the ruling is unfavorable will a party then consider further filings to the court. This is a decision made on a case-by-case basis and there is no set formula on what strategy to employ, but there is a general understanding that the Board of Appeals has more expertise than the courts, particularly in complex customs disputes.

As is the case for Board of Appeals reviews, a post of security for the assessment is required during the trial court process. Court proceedings will proceed until issuance of the court judgment. There is a further right to consider an appeal to the Supreme Court, which under current rules has the right to exercise its discretion on whether to accept the appeal. If the appeal is not accepted, then the court judgment will be final and no further avenues of challenge will be possible.

Conclusion

Customs clearance and valuation are important parts of the global supply chain. In most cases, goods move freely and without negative effects. However, when customs conflicts do arise, it is critical that importers and their counsel act to assess and advocate in defense of claims. Where necessary, a well-planned and thorough defense, whether through the customs appeal process or through the courts, can reduce or otherwise eliminate assessed customs liabilities. In fact, a favorable ruling may even set a standard that reduces the likelihood of similar disputes in the future.

RELATED INSIGHTS​ 

October 24, 2025
Thailand currently lacks a specific franchise act. Consequently, the legality of any franchise agreement is determined by its compliance with various existing laws, such as the Civil and Commercial Code, the Trademark Act B.E. 2534 (1991) (as amended), and the Unfair Contract Terms Act B.E. 2530 (1997). Thailand is a freedom-to-contract jurisdiction. This allows for a high degree of flexibility and autonomy in contractual arrangements, provided that the terms do not violate any laws or public policy and do not fall under the scope of unfair contract terms. Given this, the requirement for fairness in franchise agreement terms often leads to uncertainty, but decisions from the Trade Competition Commission of Thailand (TCCT) can provide guidance on whether specific contentious terms are in fact fair.  One issue worth examining in this light is the inclusion of terms on nonrefundable franchise fees and strict purchasing conditions. Franchise Fee: Unfair to Refuse Refund? Nonrefundable franchise fees represent a significant upfront investment for franchisees, often becoming a point of contention if the franchise relationship deteriorates or the franchisor ceases operations. Their fairness and enforceability are frequently scrutinized by regulatory bodies like the TCCT, highlighting the critical balance between contractual freedom and franchisee protection. Faced with one such case, the TCCT considered whether it was unfair for the franchisor to refuse to refund the franchise fee after the franchisor ceased operations.  The franchisee had entered into a service agreement on August 2, 2021, and begun operating on October 9, 2021. However, by November 21, 2023, the franchisee was notified that the system would be shut down for maintenance, and by December 26, 2023, the franchisor announced the cessation of operations due to financial losses. The franchisee then requested a refund of the franchise fee. Unfortunately for the franchisee, the TCCT found that the franchisor’s
October 20, 2025
Global trade has become an everyday issue with immense effects on trade and the economy. Today’s global trade climate sees countries around the world engaged in trade negotiations aspiring to eliminate trade barriers. Customs tariffs and associated privileges are among the issues that most impact global trade flows and the import-export sector. Thailand has negotiated customs tariff privileges as part of its 14 free trade agreements (FTAs) with 18 countries, including six bilateral and eight regional agreements. These FTAs set forth criteria for member states to comply with and adopt into national law. To achieve customs privileges, one of the most important criteria is rules of origin, which indicate the originating country of imported or exported goods and the accompanying duty rates or privileges for reduction or exemption. Rules of Origin Under FTAs The rules of origin mapped out in FTAs allow for duty exemptions or rate reductions based on the determination of goods’ country of origin. This largely includes two main categories: Wholly obtained (WO) means the product was entirely produced in a single originating country and does not include any foreign (non-originating) content or manufacturing process. Product specific rules (PSR) are detailed criteria that define how each product’s origin is determined. PSR criteria that are often found in FTAs include “change in tariff classification” (determining origin based on sufficient transformation of materials), “regional value content” (requiring a minimum percentage of value to be added locally), and specific manufacturing or processing operations (mandating particular production steps occur in the originating country). These criteria also extend to cover other subordinated methods of verification, such as accumulation rules and de minimis rules, to provide more flexibility for the establishment of origins and tariff privileges under such FTAs. Compliance Challenges Despite attempts to promote international trade and eliminate trade barriers through
October 17, 2025
The Department of Trade under Myanmar’s Ministry of Commerce (MOC) issued a schedule of revised service fees for trade-related services, effective October 15, 2025. The revised fees are contained in Newsletter of Export/Import 6/2025, which supersedes the previous rates set out in 2018 and 2020. Service Fees The revised fees include the following: Annual fee for TradeNet 2.0, the MOC online platform for trade submissions: MMK 50,000 (approx. USD 23.81) Online service application fee: MMK 10,000 (approx. USD 4.76) Import or export license renewal (including for all imported goods exempt from the license fees): MMK 50,000 (approx. USD 23.81) for initial renewal (two months) MMK 30,000 (approx. USD 14.29) for second renewal (one month) Amendment of license information: MMK 10,000 (approx. USD 4.76) per amendment Return of export/import license: MMK 30,000 (approx. USD 14.29) Late fees for renewal/amendment of import or export license: MMK 5,000 (approx. USD 2.38) if within one month of expiry MMK 10,000 (approx. USD 4.76) if later than one month after expiry Submission Schedule License renewal applications submitted more than 14 days after the license expiration date will not be processed. Applications for license amendment must be submitted in advance of the relevant goods’ arrival at Myanmar ports or airports. For more information on this announcement, or on any aspect of import and export matters in Myanmar, please contact Tilleke & Gibbins at [email protected].
September 25, 2025
In the Thailand contribution to Labor and Employment Disputes 2026, four members of Tilleke & Gibbins’ Bangkok labor and employment team outline key aspects of dispute resolution in Thailand. Their analysis, part of Lexology Panoramic’s comparative guide covering jurisdictions worldwide, addresses the following areas: Pre-action considerations: key requirements, third-party funding, contingency fee arrangements Issuing a claim: forum, territorial jurisdiction, standing, commencing claims, fees, service, defendants and legal personality, types of claims, time limits, counterclaims Case management: procedure, rules, amendments to claims, adding parties, consolidating proceedings, class and collective actions, evidence, witnesses, tactical considerations Interim relief: availability, requirements Trial: hearings conduct and time frames, confidentiality and public access, media reporting, elements of successful claims and burden of proof Alternative dispute resolution: available types, requirements and expectations, enforcement Collective employment and labor rights: enforcement and standing Remedies and enforcement: available remedies, assessing compensation, enforcement mechanisms Appeals: procedure, time frames, other means of challenge Updates and trends: recent cases and developments, technology developments, other issues The complete Thailand chapter can be downloaded below. Tilleke & Gibbins also contributed the Cambodia and Vietnam chapters to Labor and Employment Disputes 2026. Readers can also gain 30 days of complementary access to the full Labor and Employment Disputes 2026 guide and the rest of Lexology Panoramic’s varied offerings through this link.