DAC9 introduced new rules for sharing top-up tax information and implementing filing obligations under Directive (EU) 2022/2523 (Pillar 2 Global Minimum Tax Directive).
Luxembourg’s Chamber of Deputies (Parliament) adopted, in first reading on 17 December 2025, a bill to transpose the Amending Directive to the 2011 Directive on Administrative Cooperation (DAC9, 2025/872) into national law.
The bill establishes a framework to simplify filing obligations and facilitate information exchange by multinational enterprises (MNEs) and large domestic groups under the Minimum Taxation Directive (2022/2523). It extends reporting requirements not only to EU member states but also to non-EU countries participating in relevant OECD multilateral agreements.
Under the new rules, in-scope groups must submit annual Top-Up Tax Information Returns. Luxembourg’s tax authorities will collect these returns and exchange relevant details with foreign authorities within three months of the reporting deadline, using defined spread methods to ensure only necessary data is shared.
The first reporting fiscal year covered is that starting on or after 31 December 2023, with the first submission due by 1 December 2026 via a standard form.
Companies failing to file may face penalties of up to EUR 300,000 unless proof of filing by another group entity is provided. If Luxembourg authorities are notified of delayed submissions from abroad, local entities must submit their supplementary tax information within one month.
DAC9 introduced new rules for sharing top-up tax information and implementing filing obligations under Directive (EU) 2022/2523 (Pillar 2 Global Minimum Tax Directive).
The new rules allow ultimate parent entities or designated filing entities of an MNE group to file the top-up tax information return under Directive (EU) 2022/2523. This removes the need for other constituent entities in different EU Member States to file separately. DAC9 also provides filing rules and a standard template for the return. Member States must adopt the necessary laws and regulations to comply with DAC9 by 31 December 2025.
The legislation will take effect on 1 January 2026.
Earlier, Luxembourg’s government submitted a draft bill to the parliament to implement Council Directive (EU) 2025/872 of 14 April 2025 (DAC9) on 24 July 2025.
