There are many intriguing possibilities when starting a business in Luxembourg as a freelancer, small or medium-sized business (SME), or new founder. It also means you have some important paperwork to file, and one of the most significant ones is knowing your tax identification number (TIN) in Luxembourg.
For the year 2025, having this special number is super important for all your financial transactions, from sending invoices to paying your taxes. Without it, doing business in Luxembourg will be significantly more challenging. It can affect everything from receiving payment to accessing important government services. This article explains what the Luxembourg TIN is, its importance, and how to obtain it easily.
What is a Tax Identification Number (TIN) in Luxembourg?
Whether you work for yourself, are a freelancer, or run an SME, your TIN number is the basic building block for following tax rules. It makes sure all your financial activities, like what you earn and what you spend, are correctly linked to you or your business for taxes.
Why your business needs a tax ID
For any business or self-employed individuals working in Luxembourg, having a valid tax ID isn't just a good idea — it's absolutely necessary. Without it, you will quickly face problems that can stop your business and even cause legal issues.
Here’s why your business needs a tax ID:
1. ⚖️ Following the law
Doing business in any country involves taxes. Luxembourg is not an exception — you must follow the tax laws. The tax ID in Luxembourg is a must-have for all businesses and self-employed individuals to register and comply with the country's tax rules. It's the first step to being legally recognised for tax reasons.
2. 🧾 Invoicing and payments
Imagine trying to get paid without a proper reference. YourTINis key for sending official invoices, ensuring your clients can accurately record payments to you, and facilitating smooth payment processing. Without it, clients might not want to work with you, or payments could be delayed or even refused.
3. 📝 Tax forms
Every year, businesses and individuals must submit various tax forms, including income tax and VAT forms. Your tax number is a unique identifier on all these forms, helping the ACD correctly process what you send in and determine how much tax you owe. Without it, you can't send in your forms, which means you're not following the rules.
4. 🤝 Getting services
The Luxembourg government offers many types of help, like grants and support, to businesses, especially SMEs and new companies. To access these important resources, you typically require a valid Luxembourgish taxpayer identification number. It proves that your business is operating legally in the country, making you eligible for valuable programs that help companies to grow.
5. 🌍 Working across borders
Suppose your business works with clients or suppliers in other countries. In that case, your taxpayer identification number is crucial for conducting smooth international transactions and utilising international tax agreements, such as those that prevent double taxation. It gives a recognised way to show your tax status in Luxembourg.
6. ⚠️ What happens if you don't follow the rules
If you operate without a valid tax number in Luxembourg, you could face serious problems. These can include substantial fines, delays in your business operations, inability to open bank accounts, and even legal action from the tax authorities. It can stop your business and put you at unnecessary risk.
How to get your tax identification number in Luxembourg: a step-by-step guide for 2025
Getting your TIN is usually a simple process, especially for those starting their business in Luxembourg in 2025. The exact steps can be a little different depending on whether you are an individual freelancer/solopreneur or a newly created company.
👤 For individuals (freelancers/solopreneurs)
For people who work as freelancers or solopreneurs, the social security number, also called your "matricule," often serves as your main tax identification number for your personal income tax.
- If you don't have a social security number: If you are new to Luxembourg and don't have a social security number yet, you will usually get it when you start your first job or when you register as self-employed with the Joint Social Security Centre (Centre Commun de la Sécurité Sociale - CCSS). Once you have this number, the Administration des Contributions Directes (ACD) will use it to identify you for tax reasons.
- Registering directly with the ACD: In some specific cases, if your situation doesn't automatically give you a social security number that acts as your TIN (for example, if you're not covered by a regular job or self-employment registration with the CCSS but still have to pay taxes), you might need to register directly with the Administration des Contributions Directes (ACD) to get a tax number. This usually applies if you have certain types of income that are taxed in Luxembourg.
🏢 For companies (SMEs & new founders)
For new companies, whether they are small to medium-sized businesses (SMEs) or new ventures, the tax identification number is typically given as part of the process of setting up your company:
1. Deed of incorporation
The first step is to create the "deed of incorporation" with a notary in Luxembourg. This document serves as official confirmation that you have legally created your company.
2. Registering with the business register (RCS)
After the notary step, your company must be registered with the Luxembourg Business Registers (LBR), specifically the Register of Commerce and Companies (RCS). This step is important and allows your company to exist and operate legally.
3. Automatic notification to ACD
After registration with the RCS, the Administration des Contributions Directes (ACD) is automatically notified concerning your newly created company. This notification initiates the process for the ACD to provide your company with its specific tax identification number format.
4. VAT Registration (if needed)
If your business is required to pay VAT (Value Added Tax), you must also register for a VAT number. While this is different from your direct tax identification number, both are required to comply with all tax rules. All the detailed information can be found on the Guichet.lu portal.
For all official information, always check the official Guichet.lu portal, which is Luxembourg's guide for people and businesses.
What documents you need
The exact set of documents may change over time, but as for 2025 be ready to provide the following general papers:
- 👤 For individuals: a valid ID (passport or ID card), proof of your address in Luxembourg, and, if applicable, documents related to your job or self-employment registration.
- 🏢 For companies: your company's articles of association (rules), the deed of incorporation, proof of your company's registered address, ID documents for the company's directors/owners, and any relevant business licenses.
Where to find your tax ID (TIN) once you have it
Once you have your TIN number, you need to know where to quickly find it for checking and all your tax-related tasks. It's a number you'll use often, so keep it close by.
Here’s where to find your Luxembourgish TIN number:
- Official documents from the ACD: Your tax identification number will be shown on any official letters you get from the Administration des Contributions Directes (ACD) — for example, tax assessment notices, annual tax forms, and other messages related to your taxes.
- Business registration documents: For companies, your tax ID might also be on documents related to your company's registration with the Business Register (RCS). However, the letters from the ACD are the number one source for getting the tax number itself.
- MyGuichet.lu portal: Both individuals and businesses with a MyGuichet.lu account can usually find all their tax details by logging into their online account.
- Contacting the ACD: If you've tried other methods and still can't find your tax number, the best course of action is to contact the Administration des Contributions Directes (ACD) directly. There they can help you get your number after checking your identity. You can find their contact details on their official website.
Keeping your tax information up-to-date
After getting your tax identification number, it’s important to let the Administration des Contributions Directes (ACD) know about any changes to your personal or business situation that might affect your tax status or the details connected to your TIN. This includes changes to your home address, your company's registered address, the legal type of your business, changes in who owns it, or any big changes to what your business does. Staying on top of this helps your tax records stay accurate.
This step helps you prevent problems, fines, or delays in handling your taxes, and you can usually tell the authorities about these changes through the MyGuichet.lu portal by sending a letter or by filling out specific forms, depending on what kind of update it is.
Conclusion
Understanding how your TIN number in Luxembourg works is a great start for any SME, freelancer, or new founder doing business in Luxembourg in 2025. This number is your key to managing your finances effectively, which ensures you are on good terms with the tax authorities. By following these steps and staying informed, you can confidently handle your tax duties and focus on growing your business.
If you’re ready to simplify your business administration in Luxembourg, EasyBiz.lu can help with company incorporation, accounting, and more.
