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

March 21, 2014

The DSI’s Right to Investigate Customs Violations

Bangkok Post, Corporate Counsellor Column

Business operators in Thailand should be familiar with the many administrative agencies that have regulatory and investigative authority. For example, under the Customs Act B.E. 2469, the Customs Department has the right to investigate any customs transaction that might not comply with the customs law.

By law, a customs officer may invite a business operator for one or more interviews, and may visit the operator’s office to audit and possibly attach documents and goods for further investigation, if the officer believes those documents need to be reviewed by the customs team at their office.

The Customs Department has the authority to levy very substantial taxes, duties, and fines if it concludes that the business operation is non-compliant.

Due to recent developments in Thai administrative law, in addition to the Customs Department and other agencies directly responsible for regulating business operators, the Department of Special Investigation (DSI) also has the mandate to investigate what it deems to be customs infractions or other criminal activity related to business. This means that business operators who have never been investigated by the Customs Department might still be investigated for customs violations by the DSI.

The DSI was established under the Special Case Investigation Act of 2004 and accompanying announcements (the SCI Act). The DSI is overseen and directed by the Board of Special Cases, and it is charged with investigating and examining “special cases,” which include the following:

  • Complex criminal cases that require special inquiry, investigation, and collection of evidence;
  • Criminal cases that might have a serious effect on public order and morals, national security, international relations, or the country’s economy or finance;
  • Criminal cases that involve serious transnational crime or that were committed by an organized criminal group;
  • Criminal cases involving an influential person as a principal, instigator, or supporter;
  • Certain criminal cases against administrative officials or senior police officers; or
  • Any criminal case that the Board of Special Cases determines by majority vote to investigate.

If a matter is judged to fall within the definition of the above “special cases,” the DSI will normally send the business operator a written request to attend an interview at the DSI and/or provide the DSI with a list of documents for review.

The DSI may invite the business operator to be interviewed as an accused person or as a potential witness, depending on the amount of evidence already assembled. It is possible for a business operator or members of its management to be called as witnesses, and later to be charged with the suspected crime.

Technically, a person summoned as a witness to give information to the DSI is not entitled to have a lawyer present at the interview (although discretionary exceptions are sometimes granted) and, as a general rule, anything said by a witness and recorded at the interview may be used against him or others. It is always advisable to consult legal counsel as soon as the company is first contacted by the DSI.

When there are reasonable grounds, the DSI official also has the authority to access and search any dwelling place or premises; search any person or vehicle; issue a summons or subpoena to a financial institution, government agency, or state enterprise to provide documents; and seize and attach property that is authorized under the SCI Act.

Under section 41 of the SCI Act, any person who does not facilitate lawful requests for information or evidence by the DSI is subject to imprisonment of up to one year and/or a fine of up to THB 20,000.

The above list of “special cases” might not seem very relevant to many business operators, but the Board of Special Cases recently refocused DSI resources on other business-related investigations when it issued its Announcements of the Board of Special Cases No. 4 and No. 5 in 2011 and 2012. Under those announcements, “special cases” eligible for DSI investigation now include possible infractions involving (among others) the following list of laws, entities, and agencies:

  • Consumer protection;
  • Trade competition;
  • Government agency bidding;
  • Customs, liquor, and tobacco;
  • Exchange controls, currency, Bank of Thailand and financial institutions;
  • Export tax reimbursement;
  • Trademarks and patents;
  • Industrial product standards;
  • Public companies and foreign businesses;
  • Food, pharmaceuticals, cosmetics, and hazardous substances; and
  • Minerals.

One would be hard-pressed to identify a business operator that does not fall under the purview of the recent announcements from the Board of Special Cases. Thus, almost every business could potentially be subject to a DSI investigation, even when other directly responsible agencies (such as the Customs Department or the Department of Mineral Resources) have passed on the investigation.

All business operators should keep systems in place to help them respond to the DSI and other investigations. They should also consult legal counsel as soon as they become aware of an investigation in order to help them navigate the procedural and substantive requirements, while minimizing exposure.

RELATED INSIGHTS​ 

August 11, 2026
Cambodia’s Ministry of Justice has launched a new platform on its official website to publish notices of forced sales issued by each municipal and provincial court of first instance. The platform’s stated purpose is to inform the public and facilitate greater participation in forced-sale auctions conducted in connection with court-ordered enforcement proceedings. How the Platform Works The platform publishes forced-sale notices from courts of first instance across Cambodia’s municipalities and provinces and includes a link where the public can view properties currently subject to forced sale. To participate in a forced-sale auction, individuals can download Khmer-language bidding application forms through links provided on the platform. The form typically requires the applicant’s name, sex, year of birth, identity card number and issue date, and address, together with details identifying the immovable property (including its ownership certificate number), the relevant enforcement case number and date, and the reference to the public auction or tender announcement issued by the court. Completed application forms must be submitted directly to the specific municipal or provincial court that issued the forced sale. For further inquiries about a particular forced sale, interested parties should likewise contact the relevant municipal or provincial court. Forced Sale of Immovable Property in Cambodia The publication of these notices relates to the forced sale procedure for immovable property under Cambodia’s Code of Civil Procedure (CPC). Unlike property seizure by a court, a forced sale is a compulsory execution proceeding—a subsequent enforcement step that arises only after an underlying dispute has been adjudicated and a debtor fails to pay the debt or outstanding amount due under a final and binding judgment or other enforceable title of execution. For the purposes of this procedure, the term “immovable property” under the CPC refers to land, registered buildings, jointly held shares of such property, registered
August 6, 2026
Every month, VAT-registered businesses in Thailand calculate their output and input VAT and file a return to pay the net amount due or claim a refund. Yet a common and costly dispute arises when a business that has paid input VAT to its supplier—and done everything asked of it—later finds that input VAT rejected on the grounds that the tax invoice was issued by “a person not entitled to issue tax invoices.” In these cases, a buyer may have confirmed the supplier’s VAT registration on the Revenue Department’s website, paid through the banking system, received a complete tax invoice, and kept full payment and inventory records. Even so, if the Revenue Department later determines that the supplier did not genuinely make the sale or collected the VAT without remitting it, the department can disallow the input VAT and assess additional tax, surcharge, and penalty—often more than a year after the transaction. A new article from tax and dispute resolution specialists at Tilleke & Gibbins in Bangkok examines how the Revenue Department and the courts approach these disputes, including two recent Supreme Court (Tax Division) decisions confirming that the taxpayer bears the burden of proving a supplier genuinely sold and delivered the goods and received payment. It considers why the VAT registration system offers no legal safe harbor, why the evidentiary burden falls hardest on online and cross-border transactions where buyers and sellers never meet, and how the Revenue Department’s own digital infrastructure could detect non-remitting suppliers at the source rather than shifting the loss to good-faith buyers. The article also sets out practical guidance: how to build a comprehensive “know-your-supplier” file at the time of a transaction, the procedural steps and strict deadlines for challenging a VAT assessment, and why dispute readiness belongs alongside tax planning at the center
June 29, 2026
Thailand’s cabinet has approved the draft Act on Liability for Defective Goods, commonly called Thailand’s “Lemon Law.” The Draft Act is currently pending consideration by Parliament. The draft law aims to strengthen buyers’ position in pursuing cases against sellers. While the Civil and Commercial Code offers provisions governing liability for defective goods, it is difficult in practice for buyers to successfully make a claim against sellers, particularly where defects are latent and not discoverable at the time of sale or delivery. By introducing product-specific rules and clearer remedies, the new law is intended to modernize Thailand’s consumer protection framework and align it more closely with international standards, and to help relieve the buyer’s burden of proof against the seller in product liability cases. If enacted, the draft act will take effect 180 days after publication in the Government Gazette, giving businesses a transition period to assess their compliance obligations. This article provides an overview of the key provisions of the draft act and highlights some practical considerations for businesses operating in Thailand. Scope and Key Definitions The draft act applies to sellers—defined as persons who sell goods in the ordinary course of business—and protects buyers, a term defined broadly to include not just the original purchaser but also transferees and successors in title. This expands the class of people who can bring claims. The law does not apply to used goods, live animals, or goods exempted by future ministerial regulation. It also leaves intact any separate warranties, promises, advertisements, or other guarantees a seller has given; those remain enforceable alongside the new statutory rights. General Liability for Defective Goods Sellers are liable for defects that exist at the time of delivery, regardless of whether the seller knew about them. Liability arises where a defect reduces: The benefit intended under
June 22, 2026
Arbitrator independence and impartiality form the cornerstone of a legitimate arbitral process. Under section 19 of the Thai Arbitration Act B.E. 2545 (2002), prospective arbitrators must disclose circumstances likely to give rise to justifiable doubts as to their impartiality or independence, and existing arbitrators must do so throughout proceedings. This mirrors article 12 of the UNCITRAL Model Law. Yet despite this clear mandate, practical implementation varies significantly across Thailand’s arbitration landscape. Background Thailand’s two principal arbitration institutions, the Thai Arbitration Institute (TAI) and the Thailand Arbitration Center (THAC), both maintain procedures for addressing arbitrator challenges and require compliance with the statutory disclosure obligation. Under both sets of rules, any party wishing to challenge an arbitrator must submit a challenge application within fifteen days of becoming aware of the relevant facts, and a committee is appointed to consider the matter on a case-by-case basis. The TAI additionally prescribes its Code of Ethics and Conduct for Arbitrators to further emphasize the expectation of impartiality and transparency. However, Thailand’s arbitration ecosystem extends well beyond the TAI and THAC. Several sector-specific institutions also administer arbitral proceedings, including the Thai Commercial Arbitration Office under the Board of Trade of Thailand, the Arbitration Centre of the Office of the Insurance Commission, the Arbitration Centre of the Securities and Exchange Commission, the Office for the Prevention and Resolution of Disputes regarding Intellectual Property, and the Arbitration Centre of the Thai General Insurance Association. These institutions each operate under their own procedural rules, which were developed to serve particular industries and dispute profiles. The procedural mechanisms for securing and documenting an independence declaration are not uniformly established across these forums. Consequences of Procedural Inconsistency This creates a notable gap. Not all arbitration bodies have a formalized procedure requiring written independence statements before proceedings commence. Some tribunals proceed