You’ll need to declare your Solar Staff income independently – since you’re working as a freelancer rather than an employee, Solar Staff doesn’t withhold or pay taxes for you.

Here’s what you’ll need to report your Solar Staff income in Luxembourg:

As a Luxembourg tax resident, you’re taxed on your worldwide income – it doesn’t matter where you earn it. Non-residents only pay tax on income earned from Luxembourg sources.

You become a tax resident of Luxembourg when you meet at least one of these conditions:

National identification number (Numéro d’identification nationale, NIN / Matricule) is your unique lifetime identifier. You’ll need it for filing tax returns, accessing government services, and opening bank accounts. The 13-digit number starts with your date of birth in YYYYMMDD format – for example: 1983120756731.

Luxembourg citizens get their matricule at birth when they’re registered in the National Register of Natural Persons (Registre national des personnes physiques, RNPP). If you’re moving to Luxembourg from abroad, you’ll receive yours when you file the mandatory arrival declaration (Déclaration d’arrivée) at your local municipality (here’s how).

This number pulls triple duty – it’s your tax identification number (Numéro d’identification fiscale, NIF) and your social security number (Matricule assuré) as well. You’ll find it on your social security card (carte d’identification de la sécurité sociale).

More about the matricule

VAT identification number (Numéro d’identification à la TVA) comes from the Registration, State Property and VAT Administration (l’Administration de l’enregistrement, des domaines et de la TVA, AED) when you register as a VAT payer. It’s formatted as LU (the Luxembourg code) followed by eight digits, like this: LU12345678 (verify a number here). You’ll need to register once your business activities hit certain thresholds.

Business registration number (Numéro RCS) gets assigned when you register with the Luxembourg Trade and Companies Register (Registre de commerce et des sociétés, RCS). For sole proprietors, it’s a six-character code like A12345 (look up a number).

Employer registration number (Matricule-employeur) is what you need if you’re hiring employees. You’ll use this number to work with the Joint Social Security Centre (Le Centre commun de la sécurité sociale, CCSS) and handle social security contributions for your workers. Here’s how to get one

Luxembourg offers several business structures, but when working through Solar Staff, you’ll need to operate as a sole proprietor (entreprise individuelle / indépendant).

To handle government communications and file reports online, you’ll want to register on the MyGuichet.lu portal. For login access, you’ll need either a LuxTrust electronic key (LuxTrust), an electronic identity card (e-ID), or eIDAS – any of these also work as electronic signatures.

Useful resources: portal registration; setting up your personal account (eSpace); FAQ

Here’s what you need to know about operating as a sole proprietor and handling your taxes.

A sole proprietor (entreprise individuelle / indépendant) runs their own business, owns it completely, and takes on all the risks that come with it.

Requirements for foreign nationals: You’ll need a Luxembourg residence permit that allows you to run a business, an official business address in the country, and proof of professional integrity (honorabilité professionnelle).

This status works whether you’re providing services or trading goods under your own name.

How to register. Start by getting an establishment authorization (autorisation d’établissement). You can apply online through MyGuichet.lu (see instructions) or mail a completed application form (Demande d’autorisation d’établissement (y inclus la déclaration sur l’honneur)) with your supporting documents to the address on the form. Either way, you’ll pay a registration fee of EUR 50. Expect a decision within three months.

Once you have your authorization, you’ve got eight days from your start date to register with social insurance. File the Déclaration d’entrée pour travailleurs indépendants form with the Joint Social Security Centre (Le Centre commun de la sécurité sociale, CCSS) – you can do this through MyGuichet.lu or send it by mail.

If you’re doing commercial activity, you’ll also need to register with the Luxembourg Trade and Companies Register (Registre de commerce et des sociétés, RCS), which gives you commerçant status. Apply online (here are the instructions and FAQ) and pay the registration fee (see fee schedule).

If you hire employees, make sure you understand your employer obligations.

When you’re ready to close your sole proprietorship, file a cessation notice (déclaration de sortie) with CCSS and submit all the required final reports (see what’s involved in closing).

Keep regular records of your income and expenses. Hold onto invoices, receipts, delivery notes, and other financial documents for at least ten years. More on accounting requirements

If you’re registered with the Trade Register and your annual turnover exceeds EUR 100,000, you’ll need to submit annual financial statements within seven months after the calendar year ends. These statements must follow the Plan comptable normalisé (PCN) accounting framework and be filed electronically (step-by-step guide).

As a sole proprietor, you’ll pay the following taxes and contributions:

Personal income tax (Impôt sur le revenu) is calculated on your total income from all sources – business and otherwise. The rates are progressive (2025 rates):

You can deduct business expenses (dépenses d’exploitation) when properly documented. There are also special deductions (dépenses spéciales) available for things like donations and certain contributions, plus a child tax credit (modération d’impôt pour enfant). If you have business losses, you can carry them forward for up to seventeen years if they were incurred before 2017.

There’s also a self-employed tax credit (CII / CI-CO2) that kicks in when your net income stays under EUR 80,000 per year. This credit reduces what you owe on your final tax return (more details in the FAQ).

In Luxembourg, your tax liability depends on your tax class (Article 119 of the Income Tax Law), which is determined by your marital status. There are three classes:

Here’s how tax is calculated for each class:

You’ll need to file a personal income tax return (déclaration pour l’impôt sur le revenu) using form 100. There are several ways to do this: complete it online if you meet the eligibility requirements, download the PDF version and submit it through MyGuichet.lu, or mail a paper copy to the Tax Administration at the listed address (filing guide).

Married couples file joint returns by default. If you want to file separately, at least one spouse must submit form 166 (Demande d’individualisation / taux RTS) online by March 31st of the filing year. Both spouses need to sign the form.

The filing deadline is December 31st of the year following the tax year (tax calendar). Missing this deadline can result in penalties and an additional tax of up to 10% of what you owe (penalty details).

Income tax is paid through quarterly advance payments (avances d’impôt), due on March 10, June 10, September 10, and December 10 of the year you earn the income. Each advance payment equals one quarter of your previous year’s assessed tax, though you can request an adjustment if your circumstances have changed.

Once the tax authorities review your return, they’ll send you a notice (bulletin d’impôt) showing either the additional amount you owe or the refund you’ll receive. If you owe more, you’ll have one month to pay. Late payments accrue interest at 0.6% per month (payment details).

You’ll need to pay social security contributions to the Joint Social Security Centre of Luxembourg (Le Centre commun de la sécurité sociale, CCSS). These are calculated based on your net income from the previous tax year – or, in your first year of business, based on the minimum wage. Current contribution rates for 2025 are available here.

Payment process. Contributions are paid monthly. CCSS will send you a bill (extrait de compte) that must be paid within 10 days, though you can request a payment extension if needed. Late payments incur a penalty of 0.6% of the contribution amount per month (more about contributions). There are no separate contribution reports to file.

You must register as a VAT payer if your sole proprietorship’s annual turnover exceeds EUR 50,000. You’re also required to register if you provide goods or services to EU clients, regardless of your turnover level. Voluntary registration is also permitted (registration details).

Registration requires filing a notice of commencement of activity (déclaration initiale) with the Registration, State Property and VAT Administration. You can submit this online through MyGuichet.lu or mail a paper version to the administration’s address along with a copy of your ID. Once registered, you’ll receive a VAT identification number.

The standard VAT rate is 17%, one of the lowest in the EU. Reduced rates of 14%, 8%, and 3% apply to specific goods and services, and some services are entirely exempt from VAT.

As a VAT-registered business, you must meet certain record-keeping and documentation requirements. This includes issuing proper VAT invoices to your clients.

VAT returns (Déclaration de TVA) must be filed online through the eCDF system. You’ll need to register your profile first (registration details). The return forms are available here.

Your filing frequency depends on your annual turnover:

Filing deadlines vary by frequency:

VAT must be paid by the same deadline as your return filing date (payment information).

If you provide goods or services to clients in other EU countries, you’ll need to file a recapitulative statement (état récapitulatif) that lists your customers’ VAT numbers (verify VAT numbers). These statements are filed online only, through the eCDF system (filing instructions).

The statement is due by the 25th of the month following the reporting period. Filing frequency depends on your turnover from EU transactions:

The solidarity tax is an additional levy that funds the Employment Fund (Fonds pour l’emploi). It’s calculated on your taxable income as determined in your annual return. The standard rate is 7%, but higher earners pay 9% – specifically, those earning above EUR 150,000 in classes 1 and 1a, or above EUR 300,000 in class 2.

There’s no separate filing requirement – solidarity tax is paid together with your income tax.

When reporting your Solar Staff income, use the information from your freelancer offer agreement along with data from your work completion certificates and invoices.

Reach us through the online chat in your Solar Staff account or email [email protected] – we’re here to help.