Format LU plus 8 digits, matricule versus VAT number, registering with the AED and checking a number on VIES: everything a director needs to know about their VAT number.
The short version. A Luxembourg VAT number is made up of the letters LU followed by eight digits. You obtain it by filing an initial declaration with the Registration Duties, Estates and VAT Authority (AED), within 15 days of starting your activity, through MyGuichet.lu or by post. To check a number, your own or a European client's, the official tool is VIES, the European Commission's database. This number is not your national matricule, and the distinction has concrete consequences.
The VAT number is one of those identifiers everyone uses daily without ever stopping to look at it, until the day a client disputes an invoice, a supplier refuses to apply the exemption, or you find yourself hunting for a number you no longer have to hand. Here, without detours, is what a VAT number looks like in Luxembourg, how you obtain it, how you check it and what it is actually for.
What does a Luxembourg VAT number look like?
A Luxembourg VAT identification number consists of the two letters LU followed by eight digits, for example LU12345678. The first six digits identify the taxable person, the last two act as a check key. It is this number, prefixed with the country code, that travels on your invoices and through your intra-EU dealings.
The most common confusion is with another identifier: the matricule. On incorporation, a Luxembourg company receives a 13-digit national matricule, used as its reference with the administrations. That matricule is not a VAT number, and it does not go on an invoice in its place. The two coexist, with different uses.
| Identifier | Format | What it is for |
|---|---|---|
| National matricule | 13 digits | The entity's reference with the administrations (including the AED). It does not appear on invoices as a VAT number. |
| VAT number | LU + 8 digits | VAT identification. Mandatory on invoices, and a condition of intra-EU transactions. |
Remember the simple rule: the matricule identifies the company, the VAT number identifies the taxable person. When a client asks for "your VAT number", what they want is the LU followed by eight digits, never the matricule.
How do you obtain a VAT number in Luxembourg?
The VAT number is issued by the AED at the end of an initial declaration. Anyone whose activity makes them a taxable person must in principle file this declaration within 15 days of starting that activity, electronically through MyGuichet.lu (with a LuxTrust product or an electronic identity card) or by post. Guichet.lu sets out the procedure on its official VAT registration page, consulted in August 2026.
Two points are worth stating plainly. First, the clock starts from the start of activity, not from the date of incorporation: a company formed in April that begins trading in October counts its fifteen days from October. Second, registration does not depend on your turnover. Even a small business that will stay under the €50,000 threshold and opt for the exemption scheme must notify the AED: the exemption releases you from charging VAT and filing periodic returns, not from registering. We cover that choice in our article on the VAT exemption and its €50,000 threshold.
The full calendar of first steps, from the initial declaration to the first accounts filing, is set out step by step in our guide to accounting in a Luxembourg company's first year. Obtaining the number is only one stage there, but it is the first, and the one most often missed for want of thinking about it in time.
Company being formed or activity just starting? We frame your VAT registration before the fifteen-day clock runs against you.
Frame your registrationHow do you check a VAT number, yours or a client's?
This is the second half of the subject, and often the more useful day to day. Checking a European VAT number is done on VIES, the VAT Information Exchange System run by the European Commission. You enter the country and the number, and the service tells you whether that number is valid and active for intra-EU transactions, usually returning the taxable person's name and address.
This check is not an optional formality. Since 2020, your client's valid VAT number, provided and verified, is a substantive condition of the exemption when you invoice VAT-free to a taxable person in another Member State. In other words: a number that is invalid on VIES, and it is you, the Luxembourg seller, who owes the VAT. We explain the whole mechanism in our article on intra-EU VAT in Luxembourg.
Two nuances to avoid the wrong conclusion. A number can be perfectly real without showing as valid on VIES: a small business under an exemption scheme in its own country does not always have an active number for intra-EU acquisitions. Conversely, a client who gives you a matricule or a mistyped number will fail the check for a simple format reason. When in doubt, ask for the full number in writing and check it before issuing the invoice, not after.
Where do you find your own VAT number?
If you are looking for your number and cannot find it, three places carry it. The registration confirmation issued by the AED at the end of your initial declaration, first. Your own sales invoices next, where it must appear. And your MyGuichet.lu space, where your taxable-person data is accessible. A Luxembourg VAT number is not confidential: it is meant to be shared with your clients and suppliers, and it is checkable by anyone on VIES.
What is the number for, day to day?
Once obtained, the VAT number lives mainly in three places. On your invoices, where it is a mandatory detail: an invoice issued by a Luxembourg taxable person carries its VAT number, and the absence of that detail makes the invoice contestable. In your VAT returns, filed on the eCDF platform at the frequency assigned to you, as we detail in our guide to VAT returns in Luxembourg. And in your intra-EU dealings, where it conditions the exemption and feeds your recapitulative statements.
It is this omnipresence that explains why an error on the number, a missing detail on an invoice or a neglected VIES check always ends up being paid for, often during an audit. The number is not a form-filling detail, it is the key that ties each transaction to the right tax regime.
What Advena does
Obtaining a VAT number and keeping it working properly is part of routine bookkeeping, not a separate service. We handle the initial declaration at start-up, we configure your fiscal positions in the Odoo we deploy for you so that VIES checks and invoice details are automatic, and we produce your eCDF returns. All of it in a fixed fee starting from €325 per month, all in, with no hourly billing and no charge outside the monthly fee. Want the full picture of what an accounting firm covers and what it really costs? We set it out in our complete guide to accounting firms in Luxembourg and in our article on what an accounting firm costs.
Let us be straight: to simply obtain a VAT number, you do not need an accounting firm, the MyGuichet procedure is within reach of a methodical director. Where support changes things is afterwards: choosing the right regime from the start, checking every client without thinking about it, never missing a filing frequency, and seeing a threshold breach coming before it hits. That is continuous work, not a form.
Unsure about your VAT regime, your invoice details or the validity of a client's number? We look at your situation before the next audit.
Discuss your situationFrequently asked questions
What is the format of a Luxembourg VAT number?
A Luxembourg VAT number consists of the letters LU followed by eight digits, for example LU12345678. The last two digits act as a check key. It is distinct from the 13-digit national matricule assigned to the company.
How do you obtain a VAT number in Luxembourg?
By filing an initial declaration with the Registration Duties, Estates and VAT Authority (AED), in principle within 15 days of starting activity, through MyGuichet.lu or by post. Obtaining it does not depend on turnover: even a business under the exemption scheme must register.
How do you check a Luxembourg VAT number?
On VIES, the European Commission's official service. You enter the country and the number, and the system indicates whether it is valid and active for intra-EU transactions. Checking a European client's number is a substantive condition of the VAT exemption.
What is the difference between the matricule and the VAT number?
The 13-digit national matricule identifies the company with the administrations. The VAT number, in the form LU plus eight digits, identifies the taxable person and appears on invoices. The two coexist and are not interchangeable.
Does a business under the VAT exemption have a VAT number?
Yes. A business under the exemption scheme registers with the AED and receives a number, even though it charges no VAT. That number, however, is not always active for intra-EU transactions, which is why it may not show as valid on VIES.
Read more
- Accounting firm in Luxembourg: the complete guide for an SME
- VAT exemption in Luxembourg: the €50,000 threshold
- Starting a company in Luxembourg: accounting in year one
- Intra-EU VAT in Luxembourg: reverse charge and recapitulative statements
- Luxembourg VAT returns: filing frequency, eCDF and deadlines
Why Advena?
We keep the books of Luxembourg SMEs inside the management tool we deploy ourselves, on a fee announced up front from €325 per month and with no invoice outside the monthly fee. VAT registration, checking clients' numbers and tracking returns are part of routine work, not an option. The procedures and format cited here come from Guichet.lu and the AED, and from the European Commission's VIES service, consulted in August 2026; we inform and point you in the right direction, without standing in for tax advice on your particular situation.
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