Resident and non-resident taxpayers who are subject to taxation (taxation by assessment) in Luxembourg are required to report their income by filing an income tax return (form 100). If there is no tax liability, resident and non-resident taxpayers can, upon request, file a tax return (form 100) in order to be taxed by assessment.
From the 2021 tax year, eligible taxpayers can file their personal income tax return online via an electronic assistant on the MyGuichet.lu platform if they receive the following in Luxembourg:
Taxpayers who do not fall within the scope of this electronic procedure can file their tax return by sending the PDF file of their tax return via MyGuichet.lu or by post.
All resident or non-resident persons:
These individuals must not have:
Only income received from salaried employment, a pension/annuity or the rental of goods can be declared electronically.
This procedure does not apply to anyone with the following types of income:
In the context of an electronic tax return, taxpayers cannot request or revoke:
Note: if the withholding tax forms of a non-resident couple show a tax rate, then this couple can use the electronic procedure because the assimilation mode has already been requested in advance as the rate has been entered on the withholding tax form.
Furthermore, the taxpayer cannot use this version of the electronic procedure to request or after having previously requested:
In addition, the current version of the procedure does not allow taxpayers to apply for:
With regard to extraordinary expenses, only the flat-rate deductions for disability and infirmity, domestic service costs, assistance and care expenses, as well as tax allowances for children who did not belong to the household can be claimed through the electronic procedure.
In the event of joint taxation, the declarant(s) must have:
Those who wishes to file a tax return electronically must have an eSpace on MyGuichet.lu, more particularly:
Note: if the tax return is submitted by a representative, the latter must have a power of attorney from the taxpayer (form 101) and attach it to the procedure as a supporting document. This power of attorney is not required if the representative is a lawyer.
Anyone who does not yet have a private eSpace on MyGuichet.lu can consult our tutorial which guides them step by step in the creation of their own private eSpace.
The income tax return for natural persons must be filed by 31 March of the year following the tax year concerned, and the specific submission deadlines indicated in the letters from the Luxembourg Inland Revenue's different departments must be observed.
Example: for the tax year N, the tax return should be submitted before 31 March of the year N+1.
Anyone who requires an extension of the deadline for submitting the tax return should apply for the extension (preferably by fax or post) to the competent tax office.
In the event of failure to meet the indicated deadlines, an additional tax, a late payment fee or a penalty may be levied by the tax office.
Taxpayers who refuse to file their tax return will force the tax office to determine the tax liability using the estimated assessment procedure (taxation d'office par voie d'estimation).
Taxpayers or their representatives (e.g. a fiduciary), must submit the income tax return for natural persons electronically through their private or business eSpace on the MyGuichet.lu platform.
In order to easily complete the tax return, the entry of data can be initiated by submitting an XML file on MyGuichet.lu.
The person submitting the file needs:
After initiating the process, the declarant is invited to follow the instructions provided by the assistant in order to complete the declaration.
Declarants must sign the tax return electronically at the end of the process.
Taxpayers can attach supporting documents to the electronic income tax return.
Note: depending on the declarant's situation, certain documents must be attached to the tax return.
For example, if the declaration is submitted by a representative, the latter must attach the form granting them the power to file the tax return.
The taxpayer(s) must:
Withdrawal of consent can be made by letter to the competent tax office until the tax has been accounted for.
In the case of joint taxation, the withdrawal of consent by one of the spouses is sufficient to ensure that taxation cannot be carried out exclusively by automated means.
A taxpayer who does not wish to give their consent to exclusively automated processing can file their income tax return using the form 100, which can be downloaded from the ACD's website and submitted:
Income tax return for resident and non-resident natural persons (form 100)
Déclaration pour l'impôt sur le revenu pour personnes physiques résidentes et non résidentes (modèle 100)
Einkommensteuererklärung für ansässige und nicht ansässige natürliche Personen (Vordruck 100)
Income tax return for resident and non-resident natural persons (form 100) - procedure using a business eSpace
Déclaration pour l'impôt sur le revenu pour personnes physiques résidentes et non résidentes (modèle 100) - démarche via un espace professionnel
Einkommensteuererklärung für ansässige und nicht ansässige natürliche Personen (Vordruck 100) - Vorgang über einen beruflichen Bereich