On 26 December 2024, Thailand enacted the Top-up Tax Emergency Decree to implement BEPS 2.0 Pillar Two which includes Domestic Top-up Tax, Income Inclusion Rules and Undertaxed Payment Rules.The Decree is effective for fiscal years beginning on or after 1 January 2025, with the first filing deadline being within 15 months after the last day of the ultimate parent entity's fiscal year. Executive summaryOn 26 December 2024, the Thai government enacted the Emergency Decree on Top-up Tax, B.E. 2567 (2024), which was officially published in the Royal Gazette on the same date.The Thai Revenue Department, through the Ministry of Finance, had...