How to Check a Luxembourg VAT Number on VIES

VIES (VAT Information Exchange System) is a free tool from the European Commission that tells you whether a VAT number is valid and registered for cross-border EU transactions. As a self-employed person, you should use it to check your own Luxembourg VAT number and your suppliers’ numbers regularly.

What is VIES?

The Commission calls the service VIES VAT number validation. It is a search engine (not a database) that queries each EU country’s tax authority in real time when you look up a VAT number, and it confirms whether a number is valid and can show the registered business name and address.

This matters for cross-border business: if you sell services to another EU business using the reverse charge mechanism (autoliquidation), you need a valid VAT number on both sides.

How to check a VAT number on VIES

1. Go to VIES
2. Select the country code from the dropdown (LU for Luxembourg, DE for Germany, FR for France, etc.)
3. Enter the VAT number (without the country prefix — just the digits)
4. Click Verify

VIES will tell you:

• Whether the number is valid or invalid
• The registered business name
• The registered address (in most cases — some countries restrict this for data protection)

VIES queries are real-time. If the tax authority’s system is down, you may get a “service unavailable” error. Try again later — it doesn’t mean the number is invalid.

Check your own VAT number

You should check your own Luxembourg VAT number on VIES to make sure it’s correct. Look for:

• Is it showing as valid? — if not, contact AED (Administration de l’Enregistrement, des Domaines et de la TVA)
• Does the address match your invoices? — if your VIES address says your home but your invoices say your office, that’s a problem
• Contact address vs. business address — VIES may show two address fields. We’ve seen cases where these got mixed up for clients. Check both.

If your address is wrong on VIES, you need to file a VAT address change through MyGuichet.lu. It’s free and takes about a week.

New VAT numbers

If you just registered for VAT, your number may take a few business days to appear on VIES. Don’t panic if it shows as invalid on day one — wait 3-5 business days, then check again. If it’s still not showing, contact AED.

Check your suppliers and business partners

Before issuing a reverse-charge invoice to an EU business partner, always verify their VAT number on VIES first. This protects you:

• If the number is invalid — do not accept the invoice or apply reverse charge. Ask your partner to resolve the issue with their tax authority first.
• If the name or address looks wrong — ask your partner to verify and correct it before proceeding.
• Keep proof — take a screenshot or print the VIES result and save it in your records. This is your evidence that you checked, which matters in case of a tax audit.

Practical tip: Make it a habit to check the VAT number of every new EU business partner on VIES before your first invoice. Save the result as a PDF. It takes 30 seconds and can save you major headaches later.

If your business partner doesn’t show up on VIES, they might be registered as a small business (e.g., German Kleinunternehmer). In that case, reverse charge does not apply.

What if your VIES address doesn’t match your invoices?

This is a real problem. If your registered VAT address on VIES doesn’t match the address on your invoices:

• Business clients may reject your invoices — EU VAT rules require matching details. A mismatch gives the buyer a legitimate reason to refuse.
• Platforms auto-check — Amazon validates seller VAT numbers against VIES automatically. If the address doesn’t match, your account can be flagged, funds held, or account suspended.
• Tax audits — inconsistencies raise questions.

How to fix it: File a VAT address change on MyGuichet.lu. It’s free and takes about a week.

Quick reference

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This article is for general information purposes only and does not constitute professional tax, legal, or accounting advice. Every situation is different — consult a qualified professional (tax adviser, accountant, or lawyer) for advice specific to your circumstances. BravoLisa does not accept liability for decisions made based on this information.

Last updated: September 2026. Rates and thresholds may change — always verify with the relevant authorities for the most current figures.

Sources verified on 11 September 2026: European Commission — VIES VAT number validation, Loi TVA du 12 février 1979 — coordinated text (PDF), AED — Administration de l'enregistrement, des domaines et de la TVA.