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

Similar to other types of corporate disputes, tax-related conflicts often begin with an earnest attempt to resolve matters outside the courtroom. The prospect of engaging in tax litigation can be daunting, given the potential strain on commercial relationships, the legal expenses, and the uncertainty surrounding its resolution. However, there are instances when tax litigation becomes the sole avenue for seeking redress. For individuals and entities contemplating the pursuit of tax-related legal remedies, the Thai legal system offers an accessible, impartial, and equitable platform for dispute resolution. Tilleke & Gibbins’ latest update to Tax Litigation in Thailand provides an outline for navigating tax-related disputes within the Thai legal framework. It aims to equip readers with a fundamental understanding of procedures and practices within the Thai tax litigation landscape. The full guide is available through the button below.

Thailand has introduced a comprehensive overhaul of its tax litigation procedures that will significantly impact how tax disputes are handled. The Regulations for Tax Cases B.E. 2568 (2025) take effect on November 24, 2025, and repeal the prior B.E. 2544 (2001) regulations in full. These regulations support the implementation of the Act on the Establishment of the Tax Court and Tax Case Procedure (No. 3) B.E. 2568 (2025), which expands the Tax Court’s jurisdiction to certain criminal tax matters. Published in the Government Gazette on October 14, 2025, the regulations have been reorganized into three parts covering civil cases, criminal cases, and forms, and are designed to accelerate proceedings, tighten evidentiary discipline, and modernize court operations. Structural Reform and Scope The prior regime governed only civil tax disputes. Under the new framework, the regulations introduce a dedicated chapter for criminal cases alongside updated civil procedures, as the Tax Court now has express authority to adjudicate specified criminal tax offenses. Select mechanisms applied in civil case proceedings, such as electronic communication, recording testimony, and appointing experts, also apply to criminal proceedings mutatis mutandis where they do not conflict with criminal procedure. Civil Cases: Evidence Submission, Deadlines, and Scheduling Parties must submit, together with the witness list, originals of all documentary evidence, media, or electronic data (such as files, USB drives, or CDs), and all physical evidence in the party’s possession. Failure to submit any original within the deadline (see below) results in a loss of the right to adduce that item at trial, subject only to narrow exceptions where submission is impossible due to force majeure or where receipt of the evidence is indispensable to the interests of justice. The practical impact is that parties are now obligated to assemble and verify all original documents and data at the very

Thailand’s Ministry of Finance has introduced a five-year personal income tax exemption on capital gains from the disposal of cryptocurrency or digital tokens. The Ministerial Regulation No. 399, published in the Government Gazette on September 5, 2025, offers the personal income tax exemption for transfers occurring between January 1, 2025, and December 31, 2029. The ministerial regulation was enacted to promote Thailand as a global financial center and digital asset business hub while encouraging increased domestic investment in digital assets. Key Conditions The exemption, which covers capital gains from cryptocurrency and digital token disposals during the specified five-year period, applies only to individuals. Companies that trade in digital assets are not eligible for this tax exemption. With the tax holiday set to expire in 2029 (unless extended), individual traders should plan ahead for postexemption taxation to ensure full compliance with Thailand’s personal income tax requirements. Proper documentation of digital asset transactions during the exemption period will be essential for future tax compliance. For more details on this tax exemption, or on any aspect of Thailand’s tax law and regulations, please contact Saravut Krailadsiri at [email protected] or Papavarin Sarawongsuth at [email protected].