Filing your 2026 tax return in Luxembourg

Here are the best ways to get money back on your tax return this year:

Free
myGuihet.lu Free and easy online tax return in Luxembourg
0€
per declaration
Official government tool
Secured with LuxTrust
Authorised agents for filing tax returns
0€
per declaration
See offer
Paying
Taxx.lu Online tax return in Luxembourg
59€
per declaration
Simple return with self-scanning of tax documents
Support and verification included
Discount for Spuerkeess customers
59€
per declaration
See offer
All you need to know about Luxembourg tax returns

Why declare your income in Luxembourg?

In Luxembourg, tax declaration is not always compulsory, but it can be very advantageous you can recover several thousand euros each year. On average €3,000 to €4,000 per household.

Here are the main advantages of filing a tax return in Luxembourg:

  1. Recovering tax overpayments : In Luxembourg, taxpayers are deducted as much as possible at source, without taking into account the costs they incur (insurance, childcare costs, etc.). You have to file a tax return to recover some of these costs. Filing a tax return allows you to regularise your situation and obtain a tax refund from the authorities.
  2. Take advantage of tax benefits linked to your personal situation:
    • Married couples can opt for collective taxation (which is often more advantageous).
    • Lone parents can claim a single parent tax credit.
    • Property owners can deduct interest on their mortgage and insurance premiums.outstanding balance insurance
  3. Tax optimisation: The Luxembourg system offers numerous opportunities for optimisation to increase your tax savings. By filing a tax return in 2026, you will be able to ascertain your tax situation and optimise the following three levers:
    • Application fees : optimising the costs associated with your professional activity (travel expenses, purchase of equipment)
    • Special expenses : by taking out life insurance, opening a home savings account or making donations
    • Extraordinary expenses : adjusting your childcare or household costs to maximise your tax savings

As you will have realised, even if it isn't always compulsory, filing a tax return can enable you to reclaim several hundred or thousands of euros in tax each year. Once you know your tax position, you can also optimise your tax gain through various techniques.

Please note, however, that in certain cases, Luxembourg tax returns are compulsory. In these situations, failure to make a declaration could expose you to penalties.

What do I have to declare in Luxembourg?

In Luxembourg, the obligation to declare tax depends on a number of factors, including the taxpayer's residence status, income level and personal circumstances. Understanding these distinctions is crucial to ensuring that you meet your tax obligations.

You are a Luxembourg tax resident

Luxembourg residents are required to declare all their worldwide income, whether earned in Luxembourg or abroad. However, not all residents are obliged to file an annual tax return.

Here are the main cases where a declaration is mandatory:

  1. If your annual taxable income exceeds €100,000.
  2. If you combine several sources of income (for example, two salaries or a salary and a pension) and the total amount exceeds 36,000 euros for taxpayers in classes 1 and 2, or 30,000 euros for those in class 1a (see below for tax classes).
  3. If you receive more than 600 euros a year in income not subject to withholding taxThe same applies to rents in Luxembourg.
  4. If your capital income (interest, dividends) exceeds €1,500 a year.

Even if you are not in one of these situations, you can voluntarily make a declaration to benefit from potential tax deductions.

If you are a non-resident or cross-border commuter

Non-residents, including frontier workers, have specific tax obligations in Luxembourg:

  1. Non-residents can apply for assimilation residents if they receive at least 90% of their worldwide professional income in Luxembourg. This option allows them to benefit from the same tax advantages as residents.
  2. Married non-residents who opt for collective or individual taxation are required to file an annual tax return.
  3. Non-residents must declare their Luxembourg-source income if they exceed certain thresholds or come from several sources.

It is important to note that the rules may vary according to the country of residence, depending on the tax treaties in force. To find out more, run a simulation using one of the tax return tools in our comparison.

Special cases and common questions

Here are some fairly common special cases concerning tax returns in Luxembourg:

  1. You earn more than €100,000: This threshold applies to taxable income, not gross income. Potential deductions must therefore be taken into account before determining whether you are above or below this threshold.
  2. You are married and both spouses work : combining your income is often more advantageous from a tax perspective, but requires filing a joint tax return. Consider opting for a joint tax return when declaring your 2026 income.
  3. You are changing your situation: Marriage, divorce or a change of job during the year can have a profound effect on your tax obligations. Remember to report any changes on your tax return.
  4. You receive foreign income: Even if your Luxembourg income is below the thresholds mentioned, the presence of significant foreign income may require a declaration.
  5. You are an entrepreneur or self-employed : People who are self-employed, even on a part-time basis, are generally required to make a declaration.

In conclusion, although the rules may seem complex, they are designed to ensure fair taxation for all taxpayers. If you are in any doubt about your situation, consult a tax adviser or do an online simulation on one of the platforms at the top of this page.

Tax return: key dates in 2026

In Luxembourg, the tax period corresponds to the calendar year, i.e. from 1 January to 31 December. Your tax return will therefore cover income received and expenditure incurred during this period.

Declaration deadline

The deadline for filing the tax return is 31 December of the current year. for the previous year's income. Historically, this date was set at 31 March, but this is no longer the case, unless you are married/partnered and wish to change your tax regime (for example from a joint return to an individual return). In this case, the decision must be communicated before 31 March to apply to the current tax year.

Be aware that after 31 December of the current year, it will be too late. It is impossible to obtain any extension of this deadline from the tax authorities. You will therefore no longer be able to obtain a tax refund for last year's income. You will, however, be able to file a return the following year.

Time limit for obtaining tax refund

Once you have made your declaration, it will take between 1 and 3 months to receive your refund. from the tax authorities. The tax authorities may ask you for additional documents in the meantime.

Details you need to know about income and changes during your tax year

  • All income received during the tax year must be declaredeven if they correspond to work carried out the previous year.
  • Deductible expenses must have been paid during the tax year to be taken into account.
  • If your situation changes during the year (marriage, divorce, birth of a child), these events can affect your tax liability for the whole of the tax year.

How to complete your 2026 tax return, step by step

Completing your Luxembourg tax return may seem complex, but by following this step-by-step guide, you'll be able to do it with ease. Here's how to do it:

Forms to use

The main form for Luxembourg tax returns is the model 100, which is available in two versions:

  1. Form 100F French version
  2. Form 100D German version

These forms are identical in terms of content, only the language differs. Choose the one you are most comfortable with.

You can find and download these forms on the Direct Tax Administration website. But the easiest way is to make your declaration directly onlineby using one of the tools presented in our comparator at the top of this page.

Please note that for certain specific situations, other forms may be required:

  • Form 163R (for residents) or 163NR (for non-residents) : These forms are used for the annual statement. They are used to regularise withholding tax when it is too high, particularly for people who are not required to file a full tax return.
  • Form 190F : This document is an appendix to model 100 for declaring rental income from a property.
  • Form 500/500bis : For self-employed taxpayers.

Filing tax returns online via MyGuichet.lu

Luxembourg strongly encourages the use of the MyGuichet.lu online platform to complete and submit your tax return. Here are the steps to follow:

  1. Go to MyGuichet.lu and log in with your LuxTrust certificate or electronic identity card.
  2. Select the "Income tax return" option in the "Tax" section.
  3. The system will guide you through the various sections, pre-filling in some of the information already known to the administration.
  4. You can attach the necessary documents directly by scanning or downloading them.
  5. Before submitting, carefully review all the information you have entered.
  6. Validate your declaration with your LuxTrust electronic signature.
  7. You will receive an electronic acknowledgement of receipt, so please keep this in a safe place.

With an online declaration via MyGuichet.lu...

  • Processing by the tax authorities is much faster
  • You can save your declaration and return to it at a later date.
  • Automatic checks greatly reduce the risk of errors
  • You can monitor the status of your declaration in real time

Filing tax using alternative platforms

Although MyGuichet.lu remains the official platform for tax returns in Luxembourg, alternative solutions such as taxx.lu or MyTax from Spuerkeess have emerged to meet the specific needs of taxpayers. Although these platforms charge a fee, they offer advanced features that can be particularly useful for optimising your tax return. Here is an example:

  1. The user interface is often designed to be simple and intuitiveLuxTrust's new online tax system, with dynamic forms that adapt to the specific situation of each taxpayer. There is no need for a LuxTrust certificate to connect.
  2. The data is automatically entered in the forms - simply take a photo of your documents (salary certificate, insurance premium certificate) with your phone.
  3. These platforms offer customer service and advice in real timeto help you with your tax return. You can even talk to a tax expert via live chat (useful for special cases or complex situations).
  4. They often incorporate tax optimisation algorithms who analyse your situation and make personalised recommendations to increase your tax refund.
  5. They can be used to carry out a number of tax simulations and projectionsThe simulators give you amounts in real time.
  6. In fact, these platforms offer advanced advice as an option in tax optimisation to help you maximise your tax savings.

It all depends on your situation and your expectations: if you prefer ease of use and maximum tax optimisation, then turn to one of these platforms.

The necessary documents and supporting evidence

To complete your Luxembourg tax return correctly, you will need the following documents:

  1. Salary certificates : Supplied by your employer, they detail your income and deductions at source.
  2. Pension certificates : If you receive a Luxembourg or foreign pension.
  3. Bank statements : For interest income and deductible bank charges.
  4. Insurance contracts : For deductible life, health or third-party liability insurance premiums. Generally, a certificate is issued each year by the insurance company, but this is not always the case.
  5. Proof of donation : Receipts for donations made to recognised organisations in Luxembourg (you can deduct them from your tax).
  6. Invoices : For deductible expenses such as childcare costs or energy improvements.
  7. Loan contract and interest statement : For the deduction of interest on property loans.
  8. Investment certificates : For pension savings products or home savings plans.
  9. Proof of foreign income : If you have income from other countries.

With all these documents, you will be able to complete your 2026 tax return without any problems!

The different categories of income to be declared in Luxembourg

In Luxembourg, several types of income must be declared. Understanding these categories will help you to complete your return correctly and optimise your tax situation.

1. Business income

Income from employment is often the largest part of declared income. It includes :

  • Salaries : Your employer will provide you with an annual salary certificate detailing your taxable income.
  • Income for the self-employed : If you work in a liberal or commercial profession, you must declare your profits.
  • Benefits in kind : Company cars, accommodation and meal vouchers are considered as taxable income.

Check your salary certificate carefully. Errors may be found which could affect your tax liability.

2. Wealth income

Your assets can generate taxable income:

  • Rental income : If you rent out a property, the rent you receive must be declared. You can deduct certain expenses such as interest on the loan or maintenance costs.
  • Income from securities : Dividends from shares or interest from investments must be declared. Some savings products are partially tax-exempt or offer particularly attractive tax deductions.

Good to know: Luxembourg applies a withholding tax on many types of income from securities. This simplifies your tax return.

3. Pensions and annuities

Retirement pensions and life annuities are taxable. This includes :

  • Statutory pensions paid by the National Pension Insurance Fund (CNAP)
  • Supplementary company pensions
  • Life insurance annuities

Note that some disability pensions and war victims' pensions are partially or fully exempt.

4. Other taxable income

Other types of income must be declared:

  • Exceptional income : Capital gains on the sale of assets, redundancy payments, etc.
  • Replacement income : Unemployment benefits paid by ADEMsick pay...
  • Certain foreign income, depending on the tax treaties in force between countries (check with a tax expert if this applies to you)

Please note: Don't forget to declare your foreign incomeeven if they are exempt in Luxembourg. They may influence your overall tax rate. Your tax rate in Luxembourg is calculated on the basis of all your worldwide income.

Don't hesitate to consult an expert from one of the platforms in our comparison (at the top of this page) if you are in any doubt about the taxable nature of a specific income.

How is tax calculated in Luxembourg?

Understanding the progressive tax scale

Luxembourg applies a progressive tax systemThis means that the rate of tax increases with income. This scale is divided into brackets, each of which is taxed at a specific rate.

Here are the main features of the scale for the current tax year:

  • The first €11,265 is tax-free.
  • Tax rates then range from 8% to 42%, with 23 bands in total.
  • The maximum rate of 42% applies to income in excess of €200,004.

So you pay €0 on the first band, then 8% on the part of your income in the 2nd band, then 9% on the part in the 3rd band, and so on.

Example of calculation for taxable income of €50,000 (class 1) :

  • 0 to €11,265: 0% = €0
  • 11,266 to €13,137: 8% = €149.76
  • 13,138 to €15,009: 9% = €168.39
  • …
  • 45,897 to €50,000: 39% = €1,600.17

Total tax: approximately €11,300

This progressive system ensures fairer taxationHigher incomes are taxed proportionately more as they rise.

The average tax rate

The average tax rate is a crucial concept, particularly for non-residents. It represents the overall percentage of tax paid on all taxable income. Here is the formula:

Calculating the average rate: Average rate = (Total tax / Taxable income) x 100

In our previous example : Average rate = (11,300 / 50,000) x 100 = 22.6%

The average tax rate for Luxembourg taxes is useful:

  1. For residents : The average rate gives an overall picture of the real tax burden on your total income.
  2. For non-residents: this rate is used to calculate the withholding tax on Luxembourg salaries.

The average rate is particularly important for non-resident married couples who opt for collective taxation. In this case, the tax authorities calculate an average rate based on their worldwide income, which is then applied to their Luxembourg income.

Tax payment procedures in Luxembourg

There are several payment methods in the Grand Duchy:

  1. Withholding tax : This is the main method for employees and pensioners. The employer or pension fund deducts tax directly from the salary or pension. The advantage is that there is nothing for the taxpayer to manage. The disadvantage is that the maximum amount is deducted: it is therefore essential to file a tax return to deduct expenses eligible for tax deductions (insurance, special expenses, childcare, etc.).
  2. Quarterly advances : This only applies to income that is not subject to withholding tax, such as rental income or income from self-employment. In this case, the tax authorities may require advance payments. This avoids the need for an adjustment at the end of the year, but requires good management of your accounts and finances.
  3. Payment by instalments: if you have difficulty paying your tax, you can ask the authorities to defer payment.

Understanding tax classes in Luxembourg to optimise your situation

The Luxembourg tax system is distinguished by its tax classes. Your tax class depends on your family situation. It has a direct impact on the amount of tax you pay.

The three tax classes explained

Here are the three classes of the Luxembourg tax system:

Class 1: The basic scheme

This class mainly concerns single peopleThis applies to people who have been divorced or separated for more than 3 years, or widowed after a period of 3 years. This is the least advantageous class in terms of taxation.

Class 1a: An intermediate regime

This class applies to :

  • Single people over 65
  • Single parents with dependent children
  • Widowed or divorced/separated for less than 3 years

This class offers a more favourable income allowance than class 1.

Class 2: The most advantageous scheme

This class is reserved for :

  • Married or civil union couples (provided that the Civil Partnership is recognised in Luxembourg)
  • Widows during the 3 years following the death of the spouse

Class 2 allows joint taxation of household income, which is often more advantageous.

The impact of class on tax calculation

Your choice of tax class has a direct effect on your tax rate:

  • Class 1 applies the standard scale with no specific allowance.
  • Class 1a benefits from a higher basic allowancereducing taxable income.
  • Class 2 allows tax brackets to be doubledThis can significantly reduce the tax burden for couples.

Example for taxable income of €50,000:

  • Class 1 (single), the taxpayer will have to pay around €11,800 in tax
  • Class 1a (single parent or senior): around €10,500 in tax
  • Class 2 (married or civil partnership): around €6,600 tax (for a couple on this income)

These figures are given for guidance only and may vary according to your specific situation.

Married or civil union couples: joint declaration VS individual declaration

Since 2018, married or civil union couples have been able to choose between :

  1. Collective taxation (class 2) This method is more favourable for couples with significant income disparities.
  2. Individual taxation (class 1) : This system can be more attractive for couples on similar incomes. It also allows a clear separation of tax assets.
  3. Individual taxation with reallocation of income : This advanced option allows income to be split between spouses to optimise taxation, while remaining within a system of individual taxation.

To make the right choice, we recommend running simulations with the different options.

Tax deductions to reduce tax in Luxembourg

Luxembourg's tax system offers many opportunities to reduce your tax burden. Here is a detailed overview of the main tax deductions available:

Special expenses

Special expenses are an important way of optimising your tax position. They fall into several categories:

  1. Insurance
    • Life insurance : Premiums paid are deductible up to a limit of €672 per person in the household.
    • Health insurance, home, autopremiums, and civil liability: These premiums are also deductible, up to the same overall limit of €672 per person in the household per year.
  2. Home savings Contributions to building societies are deductible up to €1,344 a year for taxpayers aged between 18 and 40 and €672 a year for those over 40. These amounts are doubled for married or civil union couples.
  3. Donations : Donations to recognised organisations are tax-deductible from €120 per year, up to a limit of 20% of taxable income or €1,000,000.
  4. Loan interest : Interest on consumer credit is deductible up to a limit of €336 per person in the household. The limits are much higher for interest on a mortgage.
  5. Retirement savings : Payments into a retirement savings plan are deductible up to 4500 € per year, regardless of the taxpayer's age.

Beware of the overall limits for certain deductions. For example, the ceiling for insurance and loan interest is the same.

Extraordinary expenses

Extraordinary charges allow you to take into account exceptional expenses that weigh on your budget, such as...

  • Unreimbursed medical expenses
  • Childcare costs
  • Disability-related expenses

The amount you can deduct depends on your income and your family situation. A flat-rate allowance of €5,400 per year can be granted for certain expensesThese include domestic costs (cleaning, etc.).

Tip: Keep all your receipts for these expenses in a safe place, as they may be requested by the tax authorities.

Tax allowances and credits

A number of tax allowances and credits can directly reduce your tax liability in Luxembourg:

  1. Allowance for child(ren) not forming part of the household: €4,422 per child under certain conditions.
  2. Employee Tax Credit (ETC) : This credit varies according to your income, with a maximum of €696 per year.
  3. Pensioners' tax credit (PTC) : Similar to the CIS, it applies to pensioners, also with a maximum of €696 per year.
  4. Single Parent Tax Credit (SPTC) : For single parents, it can be as much as €2,505 a year, depending on income.
  5. Allowance for travel expenses : A flat-rate payment of €99 per kilometre of distance between home and workplace, up to a maximum of 26 km.

The most common tax optimisation techniques in Luxembourg

Luxembourg offers interesting opportunities for tax optimisation through various insurance and savings products. Well used, these instruments can significantly reduce your tax burden while allowing you to build up a solid estate.

Tax optimization No. 1: Subscribe to a retirement savings plan

Retirement savings in Luxembourg benefit from a highly advantageous tax framework, in particular through the Article 111bis system.

Here are the tax benefits:

  • You can deduct up to 4500 € per year and per taxpayer, depending on the contributions paid into your pension savings plan
  • You will be taxed very advantageously on exit: only half of your capital is taxable. Find out more.

This allows you to build up a supplementary pension while reducing your tax bill throughout your life.

Tax optimization no. 2: Open a life insurance policy

L'life insurance in Luxembourg is a powerful tool for tax optimisation, offering advantages both during the savings phase and at the time of surrender or inheritance.

Tax benefits :

  1. Life insurance premiums are deductible up to €672 per person in the tax household.
  2. The interest generated is not taxed for the duration of the contract.
  3. After 10 years, only half the interest is taxable.

Example: A married couple each take out a life insurance policy with an annual premium of €672. Their annual tax saving, with a marginal tax rate of 42%, is : (€672 x 2) x 42% = €564.48. Over 10 years, assuming an average return of 3% per annum, they will have :

  • Paid: €13,440
  • Tax savings: €5,644.80
  • Accumulated capital of around €15,580 (excluding tax)

Tax optimization no. 3: Take out Outstanding Balance Insurance for your home loan

L'outstanding balance insuranceAlthough compulsory for many property loans, it also offers opportunities for tax optimisation.

Here are the advantages of loan insurance:

  • Premiums are deductible as a special expense, with a specific ceiling.
  • The potential tax savings are very significant when a single premium is paid
  • For contracts linked to the purchase of a principal residence, the deduction ceiling can be up to €672 x number of years of the contract (for periodic premium payments).

Example: A couple buy a house and take out outstanding balance insurance with a single premium of €20,000. With a marginal tax rate of 42% and a deduction limit of €6,720 (€672 x 10 years), their immediate tax saving is : €6,720 x 42% = €2,822.40.

In conclusion, Luxembourg offers an advantageous tax framework for savings and insurance. By understanding and using these tools wisely, you can significantly reduce your tax burden while building your wealth. A word of advice:

  • Subscribe to a plan retirement savings and pay just enough to maximise your tax gain
  • Do the same with a life insurance policy
  • And pay your Loan insurance as a single premium in order to benefit from a maximum tax refund

Special cases and specific situations

French, Belgian and German cross-border commuters: How is Luxembourg taxed?

Cross-border workers in Luxembourg are a large category of taxpayers, subject to specific tax rules.

Here's the general principle: Cross-border commuters are taxed in Luxembourg on their Luxembourg-source income. However, there are a number of reasons for this, they must also declare this income in their country of residenceThey are generally entitled to a tax credit to avoid double taxation.

Specific rules :

  • 90% threshold : To benefit from some of the tax advantages described in this article, cross-border commuters must earn at least 90% of their worldwide professional income in Luxembourg.
  • Teleworking days : There is a tolerance threshold for teleworking, above which part of the salary becomes taxable in the country of residence. This is a situation to be avoided if you wish to take advantage of tax optimisation techniques in Luxembourg.

Here's how to optimise your tax situation in Luxembourg as a cross-border commuter:

  1. If you meet the conditions, apply to be treated as a Luxembourg resident to benefit from the same tax advantages.
  2. Plan your teleworking days to stay within your country's tolerance thresholdIn this way, you can avoid partial taxation in your country of residence.
  3. Then take advantage of Luxembourg's tax deductions, such as home ownership savings, theretirement savings, l'outstanding balance insurance or life insurance.

Impatriate regime: tax benefits

Luxembourg has put in place an advantageous tax regime to attract highly qualified executives, known as the 'tax advantage'. impatriate regime" .

Eligibility requirements :

  • Be a highly qualified employee
  • Having been recruited abroad
  • Becoming a Luxembourg tax resident
  • Annual remuneration of at least €100,000

Tax benefits :

  1. Exemption from removal costs
  2. Exemption from housing costs (up to a maximum of €50,000 per year or 30% of salary)
  3. Exemption from school fees for children
  4. Exemption from impatriation allowance (up to 30% of annual remuneration)

Duration of the plan: 8 years maximum

Do a free simulation on one of the tax return platforms at the top of this page, or ask a tax expert for advice to find out more.

Taxation of foreign income: mechanisms and declaration

Luxembourg residents are taxed on their worldwide income, which includes foreign income. However, mechanisms exist to avoid double taxation.

General principles: All foreign income must be declared in Luxembourg, even if it is tax-exempt.

In the event of double taxation, there are two ways of eliminating this effect:

  • Graduated exemption : Foreign income is exempt but is taken into account in determining the overall tax rate.
  • Tax credit : Tax paid abroad is deducted from Luxembourg tax.

The income concerned is as follows:

  • Foreign property income
  • Foreign dividends and interest
  • Foreign pensions
  • Income from work carried out abroad

How to proceed:

  1. Use form 500 to declare your foreign income.
  2. Carefully document your income and tax paid abroad.
  3. Check the applicable tax treaties to understand the tax treatment of each type of income, or seek expert advice.

Expert advice on optimising your tax return in Luxembourg in 2026

Optimising your Luxembourg tax return requires a thorough understanding of the tax system and attention to detail. Here is some expert advice to help you maximise your tax benefits while avoiding common mistakes.

Common mistakes to avoid when declaring income

  1. Forgetting income : This is one of the most common mistakes. Make sure you declare all your salary income (including bonuses and benefits in kind, such as a company car), your investment income, your rental income and your annuities or pensions. All of this, in Luxembourg and abroad.
  2. Forgetting foreign income for cross-border commuters: Cross-border commuters must declare their foreign income, even if it is exempt in Luxembourg, as this enables their tax rate to be determined.
  3. Choosing the wrong tax class : For married or civil union couples, the choice between collective or individual taxation is crucial. Run some simulations to find out which option is most advantageous.
  4. Neglecting the importance of tax deductions: Don't miss out on the deductions to which you are entitled. Check all special expenses (insurance, donations, home savings), extraordinary expenses (childcare costs, major medical expenses) and loan interest on your principal residence.
  5. Incorrectly declaring amounts: Scrupulously check all the amounts you enter. A wrong figure can have serious consequences.
  6. Finally, declare too late: the deadline is 31 December each year. Don't miss this deadline!

Tax optimisation tips for your next tax return

Your first tax return in Luxembourg is important to find out your tax profile, and all the possible optimisation strategies to save you money. Here are just a few of the things you can do to maximise your tax refund:

  1. Optimise your retirement savings : Maximise your payments into a retirement savings contract (art. 111bis) up to a maximum of 4,500 € per year. If you are a couple, each spouse can benefit from this ceiling.
  2. Open a life insurance policy and make investments adapted to your sensitivity to risk: Combine life insurance and retirement savings to maximise your deductions. For life insurance policies, aim for a ceiling of €672 per person in the household. If you don't like taking risks, invest in a euro fund.
  3. Optimise your travel costs: Check that the home-work distance taken into account is correct and don't forget that the mileage allowance is capped at 26 km (for a single journey).
  4. For deductions related to your mortgageRemember to include all the costs associated with your loan (application fees, loan insurance premium, etc.).
  5. For couples: each year you should assess whether you should file a joint return or an individual return. Do a free tax simulation using one of the tools at the top of this page.

Finally, if certain causes are close to your heart, you should know that your donations can be deducted from your tax bill. In this case, plan your donations to reach the minimum threshold of €120 per year. Spread your donations over several years if necessary to stay within the limit of 20% of taxable income.

Should I call on the services of a Luxembourg tax expert?

Here are the situations in which you may need to call on the services of an expert:

  1. If your tax residence is complex : If you divide your time between several countries or if you have just moved to Luxembourg, an expert can help you to determine your tax status and the resulting obligations.
  2. If you have several sources of international income : If you receive income from several countries, an expert can help you to understand the tax treaties specific to each country, and thus avoid double taxation.
  3. If you have major property investments : If you own several properties, particularly abroad, an expert can advise you on the best tax strategy.
  4. If you have substantial or diversified assets : If you have substantial assets (shares, bonds, property), an expert can help you optimise the taxation of your income and assets.
  5. If your personal situation changes (marriage, divorce, expatriation)... These situations can have a significant impact on your tax situation and require expert advice.
  6. Finally, in the event of a dispute or problem with the Luxembourg tax authoritiesIf you have a problem, don't hesitate to call on the services of an expert.

In conclusion, optimising your Luxembourg tax return requires a methodical approach and a good knowledge of the tax system. By avoiding common mistakes, making judicious use of available deductions and knowing when to call in an expert, you can significantly improve your tax situation.

FAQ : Everything you need to know about Luxembourg tax returns

Who has to file a tax return in Luxembourg?

Not all taxpayers are obliged to file an annual tax return. The obligation applies in particular where taxable income exceeds €100,000 a year, or if the total income (wages, pensions, etc.) exceeds certain thresholds. Even where there is no obligation, it may be worth making a voluntary declaration to benefit from tax deductions.

How do I declare my tax in Luxembourg? Which forms should I use?

To declare your tax, you must use form 100F (in French) or 100D (in German). You can also file your tax return online via MyGuichet.lu. Don't forget to enclose the necessary supporting documents and send them in by 31 December of the following year.

What are the main tax deductions for optimising your Luxembourg tax return?

The main deductions not to be overlooked are special expenses (insurance, savings, donations), extraordinary expenses (childcare, sickness) and allowances. Housing-related deductions, such as interest on loans, can also reduce your tax bill.

How do cross-border commuters declare their tax in Luxembourg?

Cross-border commuters may apply to be treated as residents if they derive more than 90% of their income from Luxembourg. They must declare all their worldwide income and may benefit from specific deductions, such as the "travel expenses" lump sum. They must comply with the teleworking thresholds set by their country of residence.

What mistakes should I avoid making when filing my Luxembourg tax return?

The main mistakes to avoid are: omitting income, choosing the wrong tax regime for couples, under-utilising tax allowances, making data entry errors and failing to meet deadlines. If in doubt, consult a tax expert.

Will it be necessary to file a tax return in Luxembourg in 2026?

You don't have to file a tax return if you earn less than €100,000 a year. But it is highly recommended if you want to be able to deduct many expenses and reclaim several thousand euros in tax every year. You can do a free simulation to find out your potential tax savings.