
How to file your income tax return in Luxembourg
Many Luxembourg residents and non-residents must file a full income tax return on the modèle 100 form. Filing is mandatory if taxable income tops 100,000 euros, if non-withheld income exceeds 600 euros, or if combined salaries exceed 36,000 euros. For the 2025 tax year the return can be filed from 7 April 2026 to 31 December 2026, online via MyGuichet.lu or on paper. Those only seeking a refund can instead request an annual adjustment (décompte annuel).
