Luxembourg: Pillar Two registration and reporting forms

The Luxembourg tax authorities on January 6, 2026, made available the forms required to comply with the three main obligations under the Luxembourg Pillar Two Minimum Tax Act and launched the process on the “MyGuichet” e-filing platform.

• The forms include a registration form for constituent entities, joint ventures, and joint venture affiliates, which requires detailed information such as the identity and tax identification number of the entity, details of the multinational enterprise (MNE) group or large-scale domestic group, and information about the ultimate parent entity (UPE) and designated local entities.
• Additionally, the GloBE Information Return (GIR) XML schema has been published, aligning with the GIR materials issued by the OECD in January 2025. Luxembourg constituent entities or designated filing entities must submit the GIR unless it is filed in another jurisdiction and exchanged with Luxembourg, in which case a notification must be submitted within the same deadline.
• A local tax return for Pillar Two taxes, covering the income inclusion rule (IIR), undertaxed profits rule (UTPR), and qualified domestic minimum top-up tax (QDMTT), has also been introduced. This form allows for the election of a Luxembourg designated entity to file and pay the tax on behalf of all Luxembourg constituent entities. The return requires general information and a declaration of the amount of tax payable but does not mandate detailed calculations.

The filing deadline for these obligations is 15 months after the end of the fiscal year, or 18 months for the transitional year. Calendar-year taxpayers will have their first filing obligation by June 30, 2026, for the 2024 fiscal year.

Read a January 2026 report prepared by KPMG’s EU Tax Centre