Information for Non-Residents

Officials of the Administration des contributions directes (ACD) are there to answer any questions of a general nature relating to tax matters. Please note, however, that the ACD does not act as an independent tax adviser.

For questions relating to VAT, registration duties, death duties and transfer tax, please contact the Administration de l’enregistrement, des domaines et de la TVA (Registration Duties, Estates and VAT Authority).

Since the 2022 taxation year, natural persons who are subject to assessment (that is to say, required to file an income tax return) have been obliged to file their income tax return for the taxation year N (form 100), together with their business tax return for the taxation year N, by no later than 31 December in taxation year N+1 (the date of actual receipt by the tax office counts as the decisive date in this regard).

If the deadline for filing the income tax return is not met, this will give rise to the imposition of a surtax for late filing or non-filing, or a pecuniary penalty, or both those sanctions. As regards taxpayers who are not covered by the assessment obligation, any income tax return filed after 31 December in year N+1 is not taken into account by the Administration des contributions directes.

The deadline for filing the income tax return may not be extended beyond 31 December.

N.B. The Administration des contributions directes (ACD) does not issue an acknowledgement of receipt after a declaration has been filed.

The income tax return can be filed with the competent tax office

• in paper format;
• online via MyGuichet, using a LuxTrust product.

Outside office hours, letter boxes are available in front of the Administration’s premises for use by taxpayers wishing to deposit their tax returns in a sealed envelope.

Provided they satisfy the applicable criteria, non-resident taxpayers who are fiscally assimilated (i.e. treated as resident taxpayers for tax purposes) are entitled to benefit from the same legal provisions, and qualify for the same deductions, abatements and tax credits, as resident taxpayers. If the criteria for assimilation are fulfilled, both the local income and the foreign income of non-resident taxpayers are taken into account for the purposes of fixing the tax rate which is applicable in Luxembourg solely to local income taxable in the Grand Duchy.

The right to fiscal assimilation will only be granted on request; this is validly done by ticking the corresponding boxes on pages 3 and 4 and appending the signatures of the two spouses on page 20 of form 100 (income tax return) or by placing a tick against the relevant wording in the online income tax return (using the end-to-end digital MyGuichet procedure).

N.B. It follows that foreign income is not subject to tax in Luxembourg; instead, the amount of such income increases (or reduces) the global rate to be applied to the taxpayer’s local income. A separate letter, containing the calculation of the global rate, is appended to the notice of assessment.

The criteria to be fulfilled in order to qualify for assimilation are as follows:

* The term “professional income” covers business income, agriculture and/or forestry income, income from independent professional services, income from employment and income from pensions or annuities.

** assimilation is granted where the total foreign income amounts to less than 13 000 EUR.

These criteria are alternative and not cumulative.

Entitlement to assimilation is not affected by the applicant’s civil status and/or family circumstances. Such assimilation may be granted for unmarried persons, single parents, widows/widowers, divorced persons, persons who are judicially separated or living apart pursuant to a legal exemption or an order of a judicial authority, married persons or partners.

The 90% threshold is calculated by reference to the individual situation of each spouse/partner. Consequently, assimilation can only be applied where one of the spouses/partners satisfies the condition regarding the threshold of at least 90% of his/her total income, both local and foreign, or where one of the spouses/partners is a non-resident taxpayer and has net income not subject to Luxembourg income tax amounting to less than 13 000 euros.

Example:

Non-resident taxpayer A is married to B. A generates 100% of his/her worldwide income in Luxembourg and B generates 100% of her/his worldwide income abroad.

If A and B apply as a couple for fiscal assimilation, their application will be granted, because the whole (100%) of A’s worldwide income is taxable in Luxembourg. If they are jointly assessed to tax, the assessment will be carried out in relation to the whole of A’s local income taxable in Luxembourg, whereas, in accordance with the tax progression clause, B’s foreign income will be taken into account for the purposes of determining the global tax rate applicable to the local income.

An application for assimilation is validly made by ticking the corresponding boxes on pages 3 and 4 and appending the signature of the two spouses on page 20 of form 100 (income tax return) or by placing a tick against the relevant wording in the online income tax return (using the end-to-end digital MyGuichet procedure).

For further information, please click on the following link:

https://impotsdirects.public.lu/fr/az/t/teletravail.html

The following table summarises the differences between the two types of assessment:

*The term “income without withholding tax at source” covers business income, agriculture and/or forestry income, income from independent professional services, net income from rentals and leases, and miscellaneous net income.

If the tax class initially assigned to the taxpayer on his/her tax card was class 1a or class 2, reclassification in class 1 may trigger a corrective assessment likely to give rise to an amount due, on the basis either of an income tax return (assessment) or an annual adjustment (RTS office).

If the criteria for treating a non-resident taxpayer as a resident taxpayer (fiscal assimilation) are fulfilled, a non-resident taxpayer purchasing a property abroad for occupation as his/her main residence or for renting out is entitled to deduct the debit interest (mortgage interest) within the framework of a notional taxable base comprising local income and foreign income.

The global rate thus determined is thereafter applied solely to the local income, in order to arrive at the definitive amount of tax payable. The rental loss generated by the deduction of the debit interest reduces the tax rate applicable to the local income.

The following example serves to illustrate the difference between the taxation of a resident taxpayer and the taxation of a non-resident taxpayer:

(N.B. To make it easier to understand the difference that this example seeks to demonstrate, it is assumed here that the same taxpayer lives once in Luxembourg and once in France.

In his/her income tax return, an unmarried taxpayer provides the following figures:

Gross annual salary from employment in Luxembourg: 50 000 euros

Tax-deductible social insurance contributions: 5 525 euros

Withholding tax on salaries, deducted at source (including for the Employment Fund): 6 103 euros

Debit interest (main residence): 4 000 euros (deductible ceiling: 3 000 euros)

Insurance: 750 euros (deductible ceiling: 672 euros)

Comparison of the assessments drawn up by the ACD:

* since this negative income does not derive from a Luxembourg source, it automatically counts as exempt income reducing the notional amount of taxable income on the basis of which the global tax rate is fixed.

(1): for the purposes of this comparison, the lump-sum travel expenses have been ignored.

(2): personal/habitual residence in Luxembourg

(3): personal/habitual residence in France

As regards the private sector

The double taxation treaties concluded between Luxembourg and Germany, Belgium and France lay down tolerance limits determining the maximum number of days in a year which can be spent in a country other than Luxembourg without affecting the taxation of the whole of the salary of the person concerned in Luxembourg.

The various tolerance limits are as follows:

• for residents of Germany: 34 days (19 days up to 31 December 2023);
• for residents of Belgium: 34 days (24 days up to 31 December 2021);
• for residents of France: 34 days (29 days up to 31 December 2023).

If the limit in question is not exceeded over the course of a taxation year, Luxembourg retains the right to tax the whole of the salary.

If that limit is exceeded, Luxembourg is not entitled to tax the salary earned for work done outside its territory.

N.B. For the purposes of calculating the threshold, all days worked are to be taken into account, even in the case of part-time working or days with reduced working hours.

The foregoing provisions are not exclusively applicable to teleworking; they also apply with regard to any other professional stay or time spent working outside Luxembourg, such as a business trip or continuing training.

As regards the public sector

Remuneration paid by the Luxembourg State for services rendered to that State are in principle taxable in Luxembourg, unless:

• for residents of France: the services are rendered in France and the recipient of the remuneration has French nationality without at the same time having Luxembourg nationality (double nationality)
• for residents of Belgium: the services are rendered in Belgium and the recipient of the remuneration has Belgian nationality without at the same time having Luxembourg nationality or has Belgian nationality and another nationality other than Luxembourg nationality. In such cases, the tolerance threshold of 34 days must once again be taken into account.

Examples:

A Belgian national residing in Belgium works for the Luxembourg Ministry of Health. 40 days are spent teleworking in Belgium and 177 days are spent working in Luxembourg. Belgium is entitled to tax the remuneration relating to the 40 days, pursuant to Article 15 of the Tax Treaty, given that the tolerance threshold (34 days) is exceeded.

Luxembourg is entitled to tax the   remuneration relating to the 177 days spent working in Luxembourg.

A person residing in Belgium with double nationality (Belgian and Luxembourgish) works for the Luxembourg Ministry of Health. 40 days are spent teleworking in Belgium and 177 days are spent working in Luxembourg. The whole of the remuneration paid is taxed in Luxembourg, pursuant to Article 19 of the Treaty.

• for residents of Germany: the services are rendered in Germany and the recipient of the remuneration has German nationality OR he/she resides in Germany not only for the purposes of providing that service (this applies with effect from the 2024 taxation year. Prior to 2024, Germany had the right to tax the whole of the remuneration in question, regardless of the number of days).

For further information, please click on the following link:

https://impotsdirects.public.lu/fr/az/t/teletravail.html

To add a supplementary document to the income tax return before the assessment has taken place, the taxpayer has three options: he/she can either send it by post or via the contact form, or deliver it in person to an official in the natural persons tax office dealing with the file.

The address of a given tax office can be found by clicking on the link Compétences et adresses - Profil de l'Administration - Administration des contributions directes - Luxembourg (public.lu)

You can find out the office hours (opening and closing times) of the tax offices by clicking on the link https://impotsdirects.public.lu/fr/az/h/heures.html

If you, as a non-resident taxpayer, have any questions concerning the notice of assessment, you can either fill in the contact form appearing on the website of the Administration des contributions directes or contact your natural persons tax office directly by telephone.

The competent offices for non-resident taxpayers are as follows:

• the Luxembourg Y office for persons residing in France,
• the Luxembourg Z office for persons residing in Germany, and
• the Luxembourg X office for persons residing in Belgium and the rest of the world.

To find the telephone number of a particular office, please click on the following link: Compétences et adresses - Profil de l'Administration - Administration des contributions directes - Luxembourg (public.lu)

Income earned by you, as a non-resident, from independent professional services in Luxembourg is liable to income tax in Luxembourg only if you have a permanent establishment there.

If you need information concerning your tax card, you can either fill in the contact form appearing on the website of the Administration des contributions directes or contact the RTS non-residents office by telephone or e-mail.

To find the address of the RTS non-residents office, please click on the following link: Service d'imposition - Section RTS, retenue d'impôt sur les traitements et salaires - Profil de l'Administration - Administration des contributions directes - Luxembourg (public.lu)

The RTS non-residents office deals with the creation or modification of tax cards for non-resident taxpayers.

Any change at the level of a non-resident taxpayer’s employment will automatically give rise to the creation of an adjusted tax card, without the taxpayer having to do anything.

By contrast, a non-resident taxpayer needs to take active steps when it comes to updating his/her address or civil status. He/she should notify the RTS non-residents office of the change in question, via form 164 NR. Where a tax card is to be modified, the relevant supporting documents (residence certificate, marriage certificate, etc.) must be annexed to the application.

Notice of a change of address can also be given online via “guichet.lu”. To apply for the updating of your residential address or family status (marriage, divorce, civil partnership (PACS)), you don’t need a LuxTrust certificate. The application in that regard, accompanied by a residence certificate, is transmitted electronically to the Luxembourg administrative authorities. As soon as the modification in question has been registered, the new data are transmitted to the RTS non-residents office, which will thus be in a position to update the taxpayer’s tax card.

In the event of any modification, a new tax card is sent by post to the taxpayer concerned, and electronically to his/her employer(s).

It should further be noted that, since 1 January 2023, the annual tax cards (for resident and non-resident taxpayers) have been definitively replaced by multi-annual tax cards.

These new tax cards remain valid until such time as a change occurs which requires them to be updated (change of address, new employer, change of tax class, tax rate on the tax card, tax abatements not automatically carried over from the previous taxation year etc.). Consequently, the wage earner or pensioner is no longer automatically sent a tax card by post each year; this only happens when a new tax card is created on account of a change or changes to one or more entries.

To find the address of the RTS non-residents office, please click on the following link: Compétences et adresses - Profil de l'Administration - Administration des contributions directes - Luxembourg (public.lu).

A modification of the tax rate entered on the tax card of a non-resident taxpayer who is fiscally assimilated to a resident taxpayer may be requested using form 166. The form, duly completed and signed, should be sent to the RTS non-residents office (RTS NR). Alternatively, you can apply online via the electronic procedure available on MyGuichet, which you can find in the same place as the form on the ACD’s website.

Form 166 is available via the link Fiche de retenue d’impôt (RTS) – Formulaires - Administration des contributions directes - Luxembourg (public.lu)

The tax rate appearing on the tax card is determined by reference to the income of the non-resident taxpayer (or of his/her household in the case of joint assessment).

If the non-resident taxpayer files an income tax return (form 100), the rate determined by way of assessment is automatically shown on his/her tax card for the purposes of calculating the withholding tax on his/her salary or pension, but only where is diverges by at least 1% from the rate initially entered.

If the status of a jointly taxable married couple changes from that of a resident to a non-resident taxpayer, the initial classification in tax class 2 is automatically changed to tax class 1 by the Administration des contributions directes. Thereafter, the taxpayers concerned may lodge an application to be assimilated to resident taxpayers for tax purposes.

If the criteria for assimilation are fulfilled, the tax class shown on the tax card of a jointly taxable married non-resident taxpayer is replaced by a tax rate corresponding to the rate for tax class 2 that would apply to him/her if he/she were a married person residing in Luxembourg and jointly taxable there with his/her spouse in respect of his/her local and foreign income.

In a non-assimilated, non-resident tax household (individual or joint) having more than one tax card, the income (salary or pension) which is the highest and the most stable is taken as being equivalent to the first tax card to be assessed in accordance with the scale of withholding tax on salaries or pensions. Any supplementary (or additional) tax card is assigned a tax rate determined on the basis of the tax class of the taxpayer in question.

Set out below is a table summarising the rates applied on the additional cards:

⁽¹⁾  In certain cases, the rates of withholding tax may be reduced on application to the RTS non-residents office. In order to obtain a reduced rate, copies of the last three months’ salary certificates (of both spouses) must be attached to the application for modification (form 164 NR), marked “please consider my rate at the lowest”.

Where such an application results in a shortfall of withholding tax (for example, in the event of an increase or fluctuation in the salary/pension amounts), it will if necessary be rectified in the taxpayer’s disfavour at the end of the taxation year, by way of either a special adjustment or an income tax return.

⁽²⁾ In the case of married non-resident taxpayers who are jointly taxable, the tax class is not entered on the tax card of the non-resident taxpayer; instead, a taxation rate is entered on it (on condition that the two spouses jointly apply for that rate to be entered on the tax card). That rate corresponds to the rate that would be applicable to non-resident taxpayers if they were resident in Luxembourg and taxable there in respect of both their local and their foreign income.

⁽³⁾ For further information, please click on the following links:

https://impotsdirects.public.lu/fr/az/v/veuf.html

https://impotsdirects.public.lu/fr/az/d/dispo_trans.html

The tax abatements in question must be renewed annually using form 164 NR, duly completed and accompanied by supporting documentation. This applies in respect of abatements of all kinds (e.g. the single-parent tax credit, exceptional charges, alimony, etc.), except for the lump-sum allowance for exceptional charges in respect of people with disabilities and persons who are infirm, which continues automatically to be entered until such time as the taxpayer applies for a modification.

After the end of the taxation year, the tax abatements entered on the multi-annual tax card are cancelled (except for the lump-sum allowance for exceptional charges in respect of people with disabilities and persons who are infirm) and are only renewed upon application.

The following abatements and tax credits do not need to be applied for annually:

travel expenses, the spouse allowance and tax credits other than the single-parent tax credit.

The deadline for filing the annual adjustment for year N is 31 December in year N+1.

That deadline is an extinctive time-limit; it cannot be extended.

An annual adjustment filed after 31 December in year N+1 will not be taken into account by the Administration des contributions directes.

Non-resident wage earners and pensioners who are not taxable on an assessment basis (and who are thus not eligible to file an income tax return) may submit to the RTS non-residents office a request for withholding tax relief by annual adjustment (using form 163 NR), provided they fall within one of the following categories:

1. wage earners who have worked in Luxembourg for at least nine months of the taxation year and have carried on their salaried activity there on a continuous basis throughout that period^(*);
2. spouses who do not satisfy the conditions whereby a non-resident taxpayer is assimilated to a resident taxpayer. In such cases, the right to annual adjustment is granted if the prerequisites set out in point a) are fulfilled by at least one of the spouses;
3. wage earners who have worked in Luxembourg during part of the taxation year and who do not satisfy the conditions set out in points a) and b), provided their gross local salary/wages accounted for at least 75% of their total gross annual salary/wages;
4. wage earners or pensioners as referred to above who are entitled to a tax abatement for a child and to whom no allowance for children (family allowances, State financial aid (by way of a grant) for higher education, volunteer support) has been awarded for the same child;
5. wage earners or pensioners as referred to above who are entitled to a tax credit for a child.

(*) In order for the salaried activity to be regarded as continuous, it is a formal requirement that it is carried on, in principle, every working day in Luxembourg over a minimum period of nine months.

Non-resident wage earners or pensioners not falling within the categories referred to above may apply for withholding tax relief on wages, salaries or pensions if they declare all their worldwide income (local and foreign income).

On the basis of that “worldwide taxable income”, a tax rate is determined which is thereafter applicable solely to the local (Luxembourg) income which is subject to annual adjustment.

Any excess arising from an annual adjustment is refunded to the wage earner or pensioner concerned. No additional tax liability will in principle be collected, save pursuant to provisions relating to a special annual adjustment.

N.B. Only the expenses listed in form 163 NR are deductible. Special expenses such as debit interest, insurance, building saving contracts, old-age pension contracts, gifts, etc. are only deductible in the context of an income tax return (form 100).

The form, duly completed and signed, and accompanied by the relevant supporting documentation, should be sent to the RTS NR office.

To find the address of the RTS non-residents office, please click on the following link: Compétences et adresses - Profil de l'Administration - Administration des contributions directes - Luxembourg (public.lu)

For further information, please click on the following link:

Décompte annuel pour salariés - A à Z - Administration des contributions directes - Luxembourg (public.lu)

The “certificat de salaire, de retenue d’impôt et de crédits d’impôt bonifiés” (certificate in respect of salary, withholding tax and tax credits) must be attached to the request. The ACD reserves the right to call for additional supporting documentation within the framework of its investigative remit.

Each taxpayer is assigned a tax class. The main distinctions drawn are between unmarried persons, single parents, married persons, persons in partnerships and widows/widowers, divorced persons and persons who are living apart or judicially separated pursuant to a legal exemption or an order of a judicial authority.

It should be noted that non-resident persons who are living apart or judicially separated pursuant to a legal exemption or an order of a judicial authority are regarded for tax purposes as married persons until such time as the marriage is dissolved by divorce or comes to an end by reason of the death of one of the spouses.

The following table summarises the different tax classes applicable to non-resident taxpayers generating professional income, including pensions, in Luxembourg:

(1) Further information can be found in point 1.4. of the section “Income tax return”.

(2) The conditions for assimilation of a non-resident taxpayer to a resident taxpayer must be satisfied.

(3) In this case, the tax class is not entered on the non-resident taxpayer’s tax card; instead, a taxation rate is entered on it corresponding to the rate that would be applicable to non-resident taxpayers if they were resident in Luxembourg and were taxable there in respect of both their local and their foreign income.

Applying for assimilation or individual assessment automatically gives rise to the obligation to submit to taxation by way of assessment.

(4) For partners, applications for joint assessment and individual assessment can only be made by filing an income tax return. During the taxation year concerned, the partners retain tax class 1 or 1a (in the case of a partner having one or more children in his/her household) on their respective tax cards.

(5) Divorced persons and widows/widowers are, in principle, classed in tax class 1 (taxation under the ordinary system). However, divorced persons may apply to be assimilated to resident taxpayers in order to qualify for classification in tax class 2. In such cases, the transitional period comprises the three years following the year in which the divorce occurred, and during which the taxpayers retain the right to be classed in tax class 2. Divorced persons who were judicially separated or living apart pursuant to a legal exemption or an order of a judicial authority on 1 January of the year of the divorce may apply for the transitional phase to apply already as from the year in which the divorce takes place. The transitional phase is likewise applicable to widows/widowers as from the year following that in which their spouse died.

Further information can be found via the link Revenus professionnels - A à Z - Administration des contributions directes - Luxembourg (public.lu)

A child may not belong to more than one tax household during the course of a calendar year. If he/she moves from the household of one parent to that of the other, it is the parent in receipt of the first payment of the family allowance to which the existence of the child gives rise during the course of the taxation year concerned who retains the right to classification in tax class 1a for that year.

Where, on the other hand, the family allowance, financial aid for higher education or volunteer support is paid to the child, having attained his/her majority, that child is deemed to form part of the household of the taxpayer in which he/she is living at the start of the taxation year in question.

N.B. In the case of alternating custody without any determination of what constitutes the child’s main residence, the tax office will accept the parents’ choice as to which household the child belongs to.

From a tax point of view, unmarried persons living together form two distinct households, despite the fact that they are sharing a home.

Where the parents have more than one joint child, all of the joint children form part of the household of the parent in receipt of the first payment of the family allowance for the oldest joint child. That parent is in principle classed in tax class 1a.

If the amount shown on the statement of account is preceded by the minus sign “-”, that is to say, a negative number/balance is involved, the taxpayer is entitled to a tax refund. If, on the other hand, the amount is not preceded by any sign, this means that a tax liability is still outstanding and payable. That amount is to be paid to the bank account of the Administration des contributions directes, stating the file reference number and the taxation year concerned.

Where there is an overpayment of prepayments over the course of year N, the excess is not in principle reimbursed; instead, it is offset against the amount found to be payable when the statement for taxation year N is drawn up.

You can find details of the bank accounts by clicking on the link Service de recette - Profil de l'Administration - Administration des contributions directes - Luxembourg (public.lu).

The negative balance (amount to be refunded to you) appearing on the statement of account is normally paid into your account within 5 to 10 working days following receipt of the statement of the assessment concerned, provided you have a Luxembourg bank account and provided your bank details are known and correct.

Payment of a tax refund into a foreign bank account of the taxpayer may take a while longer (on average, up to three weeks).

Where a taxpayer receives a statement showing a balance that is due and payable, he/she may request extra time in which to settle his/her tax indebtedness. That request must be in writing and must be duly justified by a statement of reasons; it must also be accompanied by all relevant supporting documentation, and must be submitted to the competent tax office before the deadline for payment of the balance due (the date of actual receipt by the tax office counts as the decisive date in this regard).

An extension of time for payment does not constitute a right to which the taxpayer is entitled, but rather the grant of a favour. The official dealing with the request for an extension will assess whether or not it is justified. If it is approved, a letter containing details of the instalments to be paid will be sent automatically to the person making the request.

On the other hand, no extension of time will be granted where the taxpayer’s financial situation is such as to enable him/her to easily discharge his/her tax indebtedness or he/she has not yet paid his/her tax prepayments.

In the case of joint assessment, the spouses/partners are jointly and severally liable, on an unlimited basis, to pay any outstanding amounts of tax due. Consequently, each spouse/partner is required to pay the whole of the tax debt, and each spouse/partner may be pursued for the entirety of the debt in the event of enforced recovery. In other words, they must reach an amicable agreement for the purposes of discharging their tax indebtedness, failing which proceedings may be brought against them.

It is not possible to apportion the amount due in such a way as to reflect the shares respectively payable by each spouse individually.

Every due date must be respected. The expiry of a deadline for payment triggers an obligation to pay default interest at the rate of 0.6% per month on the amount of tax due.

A taxpayer seeking additional time for payment may submit a duly reasoned written request to the competent tax office, either by post or via the contact form. Such request must be lodged before the deadline for payment of the balance of tax due (the date of actual receipt by the tax office counts as the decisive date in this regard).

You should send an e-mail to the competent tax collector’s office, indicating your account number. Such request must, without fail, contain a statement of bank details (relevé d’identité bancaire - RIB) or a letter from your bank confirming that you are the holder of the bank account in question.

The fixing of tax amounts, prepayments and penalties falls within the remit of the tax offices. Please get in touch with the competent tax office, which will be happy to provide you with detailed information concerning the origin of the amounts outstanding and the way in which they have been determined.

Each payment made by you must precisely indicate, in the relevant communication, the type of tax and the taxation year to which your payment relates, failing which the tax collector’s office will allocate your payment in accordance with the allocation rules set out in §123 of the Loi générale des impôts (General Law on Taxes).

If you have any questions, please click on the following link to find the competent tax collector’s office: Service de recette - Profil de l'Administration - Administration des contributions directes - Luxembourg (public.lu).

The tax collector’s office has the right to offset, against any excess amount(s) in your favour, other amounts that are due from you. This may be done within one and the same tax file in order to offset surpluses against debit amounts, or indeed between different tax files (e.g. where the taxpayer has more than one tax file within the administration).

As a general rule, the tax office will send a letter to the taxpayer in order to notify the latter of the offsetting.

The fixing of default interest is provided for in the Tax Law, together with the way in which it is calculated. Consequently, the tax collector’s office is unable to cancel a legal requirement.

Default interest starts to run as from the first day of the month following that in which the tax debt became due, and is charged at the rate of 0.6% per month. The month in which payment is made counts as an entire month. It follows that, regardless of whether the payment takes place on the first or the last day of the month, the interest will be due for the whole of the month during which the payment is made.

Neither a protest nor a complaint affects the payability of the tax debt concerned. The recovery of that debt cannot be suspended, and in the event of non-payment, the tax collector’s office has the right to compel you to pay up by all legal means.

After lodging your protest with the Director of the Administration des contributions directes, you can submit a written application for a stay of enforcement to the tax office which issued the notice of assessment in question.

N.B. The grant of a stay of enforcement is not a vested right; in arriving at its decision, the tax office enjoys a discretionary power.

Tax debts generally lapse and expire after five years (in certain cases, 10 years).

Waiver of limitation is an act whereby the taxpayer declares that he/she waives, vis-à-vis the Administration des contributions directes, any such limitation in time of his/her tax indebtedness.

Such a waiver of limitation must be registered before the limitation takes effect, thus before 31 December in the year in which the limitation period comes to fruition.

If you do not sign and return the document to the Administration des contributions directes, it will be obliged to interrupt the limitation period by some other means, i.e. by an order to pay or by an attachment of your account or your salary.

As far as the Administration des contributions directes is concerned, the identity of the person from whom the transfer of funds originates plays a subordinate role. The important thing is that a third-party payor should clearly state your tax file number in his/her bank transfer communication.

Prepayments are fixed by the tax office, which bases its calculation on the most recent assessment carried out or, in the absence of any previous tax return or assessment, on an estimate of your income.

Such prepayments fall due for payment on the dates indicated in the statement. Failure to make those prepayments gives rise to default interest and may result in enforced recovery measures on the part of the tax collector’s office.

If you consider that the prepayments fixed are too high, you should get in touch with the competent tax office, which may, where appropriate, carry out a recalculation.

However, as long as the prepayments are not reduced or cancelled, the tax collector’s office will proceed to collect them.

When a request is made for rectification of a recently issued notice of assessment, this is known as an “application for revision”.

A taxpayer wishing to apply for a one-time revision of his/her notice of assessment, for example by reason of his/her having forgotten to include an important document when drawing up his/her tax return, may lodge an application for revision within three months following notification of the initial notice of assessment. Such an application must be sent by post to the competent tax office, accompanied by all relevant supporting documents; any corrective notice issued must likewise be notified within three months.

You can address your complaint:

• either to the relevant official in your tax office, who will pass it to the Director of the Administration des contributions directes, or
• directly to the Director of the Administration des contributions directes.

The Director of the Administration des contributions directes will be called upon to rule on the complaint.

It is recommended that you submit your complaint in writing.

Exceptionally, you may make your complaint orally to the relevant official in your tax office. In that event, the complaint will only be valid if it has been duly recorded in a signed written document.

A complaint made by fax will be accepted, but a complaint made by telephone or by e-mail will not be.

You may express yourself in one of the three official languages of the Grand Duchy of Luxembourg, namely Luxembourgish, French or German.

The Director’s decision on your complaint will be formulated, in principle, in the language of the application relating thereto.

In principle, it is the taxpayer contesting a decision of the tax office who has the right to submit a complaint to the Director of the Administration des contributions directes.

A third party may also be instructed to submit the complaint. In such a case, that third party acts as the representative and proxy of the person against whom the decision of the tax office has been issued.

That third party must hold an express, special mandate, that is to say, a written power of attorney clearly expressing the taxpayer’s intention to confer on the proxy power to act on his/her behalf by way of a complaint against the decision at issue.

In the case of representation by a lawyer, the latter automatically holds a mandate.

The Tax Law provides for various remedies against decisions of the Administration des contributions directes:

1. A protest against a notice of assessment or, as the case may be, another administrative decision must be addressed to the Director of the Administration des contributions directes within three months from the date of notification of the notice at issue.
2. A formal hierarchical appeal (“recours hiérarchique formel”) may be brought against a discretionary decision taken by the tax office (e.g. refusing to extend a deadline for payment, or fixing a surcharge). It must likewise be addressed to the Director of the Administration des contributions directes within three months from notification of the decision at issue.

Where the last day of the period is a Saturday, Sunday or statutory public holiday, that period is extended until the next working day. Once that period has expired, the complaint will be deemed to be out of time and thus inadmissible.

The complaint (protest or formal appeal to a higher administrative authority) must contain:

• the name and address of the complainant (i.e. the person lodging a protest or a formal hierarchical appeal against a severable act);
• the decision that you wish to contest, for example:
  “protest against the notice of assessment to income tax, dated 12 December 2002, for the year 2001”,
  “formal appeal to a higher administrative authority against the fixing of a surcharge for late filing amounting to 10% of the amount of tax fixed by the notice of assessment for the year 2001”

The complaint must be submitted within three months from notification of the decision at issue.

Where the last day of that period is a Saturday, Sunday or statutory public holiday, it is extended until the next working day.

Once that period has expired, the complaint will be deemed to be out of time and thus inadmissible.

It is recommended that you submit a separate complaint for each contested decision.

Example: you receive the 2022 and 2023 income tax assessment notices on the same day and you wish to lodge a complaint against both notices. Since there are two notices in all, thus two separate enforceable decisions, you should lodge two separate protests.

The Director of the Administration des contributions directes may either reject your complaint or declare it to be well founded (or partly well founded), or may annul the decision of the tax office.

The Director’s decision may be the subject of an appeal, to be lodged within three months from notification thereof before the Tribunal administratif (Administrative Court). An appeal against the judgment of the Tribunal administratif may be lodged before the Cour administrative (Higher Administrative Court) within 40 days after notification thereof.

In the absence of a decision by the Director within six months following the submission of the protest, the protest may be regarded as having been rejected, and you have the right to lodge an appeal before the Tribunal administratif against the initial tax decision (notice of assessment). 

However, following the expiry of that six-month period, the matter does not necessarily have to be brought before the Tribunal administratif, and the Director’s decision may still be issued after that period has expired.

In the event that, more than six months after lodging your protest, you have still not obtained any decision on the part of the Director, you may:

• either wait to receive the Director’s decision concerning your protest; or
• lodge an appeal against the decision forming the subject-matter of the protest, before the Tribunal administratif, 1, rue du Fort Thuengen, L-1499 Luxembourg. The application instituting the appeal proceedings must contain the appellant’s surname(s), first name(s) and domicile, must specify the decision against which the appeal is being brought, must include a summary of the facts and pleas relied upon, must state the subject-matter of the application, and must contain a schedule of the documents on which the appellant intends to rely.

If the appellant resides abroad, the appeal must in addition give an address for service in Luxembourg. The original and four copies of the notice of appeal, duly dated and signed, must be lodged with the Court Registry, accompanied by the contested notice of assessment and the documents listed, in quadruplicate.

You are required by law to refer the disputed matter in the first instance to the Director of the Administration des contributions directes. If you fail to do so, the Tribunal administratif will declare your application inadmissible.

You may:

• represent yourself;
• arrange to be represented by
  • a lawyer,
  • a chartered accountant (expert-comptable), or
  • a company auditor (réviseur d'entreprises),

      duly authorised to practise his/her profession.

An appeal may be lodged against the judgment of the Tribunal administratif (Administrative Court) before the Cour administrative (Higher Administrative Court) (time-limit: 40 days).

No right of appeal lies against the decision of the Cour administrative.

A distinction needs to be drawn between:

• objective equity, which is designed to rectify a rule or norm that proves to be unjust in a particular case, by reason of the fact that it results in taxation running counter to the intention of the legislature, and
• subjective equity, involving the personal situation of the taxpayer, where payment of the tax would have the effect of compromising his/her economic existence and depriving him/her of essential means of subsistence.

• A non-contentious appeal does not involve any dispute as to the lawfulness of the notice of assessment; it is limited to a plea for consideration to be given to questions of equity.
• By contrast, disputes concerning the application of the law, the evaluation of the taxable base or the omission of a deduction fall within the jurisdictional framework of contentious judicial proceedings.

You should address your request to the Director of the Administration des contributions directes (ACD).

Your request must be submitted by no later than the end of the year following the year in which the events prompting you to make the request took place.

In principle, objective rigour applies as from the date of your notice of assessment, and subjective rigour as from the time when real, ongoing financial difficulties are found to exist which are such that you are no longer able to pay your tax debts.

Your request for tax forgiveness must contain: 

• your name, address and tax number;
• in the context of objective rigour, a statement and substantiation of the reasons why you consider that the law does not correspond to your specific, particular case;

in the context of subjective rigour, details of your monthly income and expenses, and of your assets, showing that you are unable to pay the tax that you owe.

Your request for tax forgiveness must be in writing and must be sent to the Director of the Administration des contributions directes (ACD).

You may express yourself in one of the three official languages of the Grand Duchy of Luxembourg, namely Luxembourgish, French or German.

The Director’s decision on your request for tax forgiveness will be formulated, in principle, in the language chosen by you.

The Director of the Administration des contributions directes may either reject your request for tax forgiveness or declare it to be well founded.

The Director’s decision may be the subject of an application for reversal of such rejection, to be lodged within three months before the Tribunal administratif (Administrative Court). An appeal against the judgment of the Tribunal administratif may be lodged before the Cour administrative (Higher Administrative Court) within 40 days after notification thereof.

In the absence of a decision by the Director within six months following submission of the request for tax forgiveness, it may be regarded as having been rejected, and you have the right to lodge an application for reversal of such rejection before the Tribunal administratif.

However, following the expiry of that six-month period, the matter does not necessarily have to be brought before the Tribunal administratif, as the Director’s decision may still be issued after that period has expired.

You are obliged by law to submit your request in the first instance to the Director of the Administration des contributions directes. If you fail to do so, the Tribunal administratif will declare your request inadmissible.

You may:

• represent yourself;
• arrange to be represented by
  • a lawyer,
  • a chartered accountant (expert-comptable), or
  • a company auditor (réviseur d'entreprises),

      duly authorised to practise his/her profession.

An appeal may be lodged against the judgment of the Tribunal administratif (Administrative Court) before the Cour administrative (Higher Administrative Court) (time-limit: 40 days).

No right of appeal lies against the decision of the Cour administrative.

You can apply for an income certificate from the territorially competent tax office. The application can be made either by telephone or via the contact form of the Administration des contributions directes (ACD). The income certificate may either be collected directly from the competent tax office during opening hours (7.45 to 12.15) or sent by post to the applicant’s registered address.

The application to the ACD must contain:

1. the applicant’s surname and first name(s),
2. the applicant’s file number/identification number (matricule),
3. the applicant’s address,
4. the name of the authority demanding the certificate and the reason for the request.

To find a particular office, please click on the following link: Compétences et adresses - Profil de l'Administration - Administration des contributions directes - Luxembourg (public.lu)

The certificate of ownership or non-ownership is drawn by the Real Estate Valuation Section (SEVI). You can apply for it by telephone, e-mail or post.

To find the telephone number or e-mail address of the SEVI, please click on the following link: Section des évaluations immobilières (SEVI) – Compétences et adresses - Contact - Administration des contributions directes - Luxembourg (public.lu)

The offices are open to the public Monday to Friday from 7.45 to 12.15. In the afternoon, they are open by appointment between 13.15 and 17.00.

Further information concerning the opening and closing times of the offices can be found by clicking on the following link: Heures d'ouverture et de fermeture des bureaux - A à Z - Administration des contributions directes - Luxembourg (public.lu)

To find a particular office, please click on the following link: Compétences et adresses - Profil de l'Administration - Administration des contributions directes - Luxembourg (public.lu)

For all general questions concerning the taxation of natural non-resident persons, you can contact the ACD either by telephone or by e-mail or via the contact form appearing on its website.

You can also attend in person at its offices during opening hours (Monday to Friday from 7.45 to 12.15). In the afternoon, they are open by appointment between 13.15 and 17.00.

To find the telephone number of a particular office, please click on the following link: Compétences et adresses - Profil de l'Administration - Administration des contributions directes - Luxembourg (public.lu)

In Luxembourg, the national identification number of a natural person is also known as his/her “matricule” or “numéro d’identification personnelle” (NIF – personal identification number). The personal identification number of a natural person is composed of 13 digits. In the context of direct taxation, this “matricule” may also serve as the tax identification number (NIF/TIN) for natural persons.

The national identification number in Luxembourg of a legal entity is likewise known as its “matricule” or “numéro d’identification personnelle” (NIF – personal identification number). It is composed of 11 digits. In the context of direct taxation, this “matricule” may also serve as the legal entity’s tax identification number (NIF/TIN). Its structure reflects the year of formation of the legal entity and its legal form, whilst the last five digits are random, thus: YYYY FF XX XXX.

This 11-digit personal identification number must be stated in all communications with the competent offices of the ACD and on all bank transfers in favour of the Administration des contributions directes (ACD).

Please consult the following link: Service de recette - Profil de l'Administration - Administration des contributions directes - Luxembourg (public.lu).

You just need to click on the competent tax collection department to find your file.

Taxpayers (or employers) encountering problems with a Luxtrust product (token, smartcard, Luxtrust mobile) should contact the Luxtrust company on the number (00352) 24 550 550.

In the event that the data entered are not recorded, or the automatic amounts are not displayed, you should save the form on your hard drive and then manually start Acrobat Reader and open the form thus saved.

If you encounter problems in filling out, displaying or saving the income tax return form appearing on the website of the Administration, you can download the following tutorial in different formats:

Remplir une déclaration d’impôt avec l’assistant électronique — Guichet.lu - Guide administratif - Luxembourg (public.lu)

If the problem persists, you can contact the Guichet.lu Helpdesk via the link Contact Helpdesk — Guichet.lu - Guide administratif - Luxembourg (public.lu).

If you have technical questions concerning the XML format, you can contact the IT Division of the Administration des contributions directes (e-mail address: decl-pph@co.etat.lu)

To resolve problems relating to the tax cards database, employers can get in touch with the IT Division of the Administration des contributions directes (ACD) by sending an e-mail to the following address: fpe@co.etat.lu.