Since April 7, 2026, the income tax declaration forms for the year 2025 are available online.

The taxpayers concerned, in particular cross-border workers earning income in Luxembourg, have until December 31, 2026, to submit their declaration. The forms, including Form 100 for income tax, are available here: Personnes physiques – Formulaires – Administration des contributions directes – Luxembourg

Practical Information

Taxpayers can submit their declaration:

  • Via the electronic assistant on the MyGuichet.lu platform;
  • Via the PDF uploaded on MyGuichet.lu;
  • Or, if necessary, using the paper forms provided by the administration.

The ACD encourages the use of the electronic assistant, which allows for a simplified declaration thanks to pre-filled data, built-in checks, and step-by-step guidance, while also reducing the information required for future declarations.

The forms are available here: Personnes physiques – Formulaires – Administration des contributions directes – Luxembourg

Information and Support for Taxpayers

As part of the tax campaign, the ACD will organize an on-site information operation from May 18 to 22, 2026, called “123easy! Tax Week.” Teams will be present, notably in Esch-Belval and Luxembourg City, to meet taxpayers and answer their questions.

These meetings provide an opportunity for cross-border workers to receive practical assistance and answers tailored to their situation.

For more information, you can visit the official ACD website: Ouverture de la déclaration fiscale 2025 : simplifier les déclarations et renforcer le soutien aux contribuables – Archives – Administration des contributions directes – Luxembourg