Luxembourg

Luxembourg moves to implement DAC9 introducing automatic exchange of Global Information Returns

Luxembourg transposed the ninth amendment to the Directive on Administrative Cooperation (DAC9) into national law, with entry into force on January 1, 2026. 

As a reminder, DAC9 establishes a system for the automatic exchange of information related to the OECD/G20 Pillar Two rules, designed to ensure that large multinational and domestic groups are subject to a minimum effective tax rate of 15%.

Under DAC9, in-scope groups will file a standardized Top-up Tax Information Return (TTIR), aligned with the OECD GloBE Information Return (GIR). The framework enables centralized filing of the TTIR and mandates automatic information exchange among EU member states, streamlining compliance and promoting consistency across jurisdictions. Filing responsibilities generally follow the Pillar Two architecture and may fall on the ultimate parent entity, a designated filing entity, or a local entity where required.

The first reporting deadline in Luxembourg is June 30, 2026, for the 2025 fiscal year. The new obligations apply to multinational and large domestic groups with consolidated annual revenues of €750 million or more.

As part of the law transposing DAC 9, the Pillar Two Law was also amended with the aim to reflect OECD Administrative Guidance of January 2025 on transitional treatment of DTAs as well as to introduce a “switch-off” rules applicable to the QDMTT safe harbour.