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August 6, 2026

Know Your Supplier: Protecting Input VAT in Thailand’s Digital Economy

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 of a business’s tax strategy.

Read the full article through the button below.

RELATED INSIGHTS​ 

December 31, 2021
In the last week of December, 2021, the Ministry of Justice published the Law Amending Certain Provisions of the Laws on Tax No. 01/NA, dated August 7, 2021, in the Government Gazette. The Law will come into force on January 1, 2022. The most notable amendments relate to Value Added Tax (VAT), which are summarized below. The new law also makes changes to the laws on tax management, income tax, and excise tax, which Tilleke & Gibbins will provide updates on in due course.
November 25, 2021
On September 30, 2021, Thailand’s Revenue Department released a notification prescribing country-by-country (CBC) transfer pricing reporting requirements for multinational enterprise (MNE) groups that do business in Thailand. The Notification of the Director-General of the Revenue Department Re: Income Tax (No. 408) applies to accounting periods beginning on or after January 1, 2021, with the CBC report submitted at the same time as the annual corporate income tax (P.N.D. 50) filing (i.e., within 150 days of the end of the accounting period). For example, if the accounting period ends on December 31, 2021, the CBC report must be filed by May 30, 2022. Background The CBC report functions as part of a three-tier structure, together with a global master file and a local file, as recommended by the OECD’s Base Erosion and Profit Sharing (BEPS) Action 13 report (Transfer Pricing Documentation and Country-by-Country Reporting). The CBC reporting requirement targets large MNEs, with the aim of encouraging international tax transparency, improving tax authorities’ access to information on MNEs’ global allocation of income and taxes paid, and helping governments to assess high-level transfer pricing risks and conduct economic and statistical analysis. The CBC reporting requirement will allow Thailand to exchange tax and financial information on an automatic basis with other signatories of the Multilateral Convention on Mutual Administrative Assistance on Tax Matters. This goes in tandem with the recently passed Act Amending the Revenue Code (No. 54) B.E. 2564 (2021), which empowers the director-general of the Revenue Department to exchange information with competent authorities in other jurisdictions. Entities Required to Submit CBC Reports The CBC report notification applies to MNE groups that do business in Thailand and at least one other jurisdiction and that have consolidated group revenue of at least THB 28 billion (approx. USD 847.6 million) in a 12-month accounting
November 24, 2021
Attorneys from Tilleke & Gibbins have provided the latest update to the Thailand contribution to Doing Business in…, a Q&A-style guide published by Thomson Reuters Practical Law that presents an overview of the legal framework for doing business in 63 jurisdictions worldwide. The Thailand chapter of the guide outlines Thailand’s legal system and key laws applicable to foreign companies doing business in the country. The chapter specifically covers the following main topics: Legal system: Thailand’s court system and codified legal system. Foreign investment: Lists of reserved business activities, restrictions on doing business with certain jurisdictions, exchange controls and currency regulations, and grants and incentives available to investors. Business vehicles: Ordinary partnerships, registered ordinary partnerships, limited partnerships, private limited companies, and public companies. Environment: Main laws and regulations, factory operation. Employment: Laws, employment contract requirements, work permits, and termination and redundancy. Tax: Taxes on employment, tax and nontax resident employees and businesses, corporate income tax, value added tax, special business tax, municipal tax, stamp duty, dividends, interest, intellectual property royalties. Competition: Important aspects of Thailand’s regulatory regime surrounding competition, centered around the updated Trade Competition Act. Antibribery and corruption: Laws, compliance requirements, regulatory authority. Intellectual property: Patents, trademarks, registered and unregistered designs, and copyright. Marketing agreements and advertising: Regulation of marketing agreements, Thailand’s Consumer Protection Act, direct marketing, role of the Consumer Protection Board and Food and Drug Administration. E-commerce: E-commerce laws and regulations, marketing and sales via online platforms. Data protection: An outline of Thailand’s Personal Data Protection Act. Product liability: Procedures and regulations for product liability and product safety, including the Unsafe Goods Liability Act and the Consumer Case Procedure Act. Product liability: Key regulatory authorities for trade competition, environmental issues, and financial services. To browse, download, or print the Thailand chapter, please visit the Practical Law website.