On January 29, 2021, Thailand’s Revenue Department published the Notification of the Director-General of the Revenue Department Re: Income Tax (No. 400), which prescribes the criteria, methods, and conditions for Revenue Department officials on how to assess income and adjust expenses for transactions between related parties (as defined in Section 71 bis of the Revenue Code) that engage in intercompany transactions where conditions between the two parties in their commercial or financial relations differ from those that would be made between independent parties (i.e., where the transaction is not an “arms length” transaction). Those who are familiar with international transfer pricing standard practices will note that the measures under the notification generally follow the concept of chapters II, III, VI and VII of the OECD Transfer Pricing Guidelines for Multinational Enterprises and Tax Administrations. The key elements of the notification are summarized below. Accepted Transfer Pricing Methods The notification recognizes the following as accepted transfer pricing methods: Comparable Uncontrolled Price Method Resale Price Method Cost Plus Method Transactional Net Margin Method Transactional Profit Split Method The notification also requires that the arm’s length result of an intercompany transaction (i.e. the controlled transaction) must be determined using the most appropriate transfer pricing method. If none of the above transfer pricing methods is appropriate for the tested controlled transaction, the company may apply an alternate pricing method to the transaction by notifying the Director General of Revenue in writing, within the relevant accounting period, and describing the reason for doing so. Selection of the Most Appropriate Transfer Pricing Method There is no formal order of preference for the use of the five accepted pricing methods. However, the notification requires the selection process to take account of the following factors: The respective strengths and weakness of the recognized methods; The appropriateness of