When you invoice a business customer in another EU country, its VAT number matters: it's how you show the customer is a taxable person, and often why you don't charge VAT yourself. The European Commission's VIES service lets anyone check a VAT number. It's free and official, and it answers a narrower question than most people think. This guide shows what VIES confirms, with real answers we got on 9 October 2026, and why a check in the company register completes it.
What you'll learn
- What VIES is and what it confirms
- Real VIES answers for a French and a Spanish number
- The errors you'll meet and how to handle them
- What VIES doesn't tell you
- Why to keep proof of each check
What VIES is
VIES (VAT Information Exchange System) is run by the European Commission. When you check a number, the request goes to the tax administration of the country concerned, which says whether the number is registered in its national database. According to the Commission, the site exists to let persons involved in intra-Community supplies of goods or services confirm the validity of a customer's VAT number, under article 31 of Council Regulation (EU) No 904/2010.
The answer is valid or invalid. Depending on national data protection rules, some countries also return the name and address linked to the number; if they don't appear, that country doesn't allow it.
French administration pages say the same thing in practice: service-public.fr points businesses to VIES to check the VAT numbers of their customers and suppliers, to avoid fraud and scams.
Real answers
We checked three numbers on 9 October 2026, through VIES's web service:
Renault, FR63441639465. Valid. France returns a name and an address: the name came back as "SA RENAULT", and the address as the company's head office in Boulogne-Billancourt. Note the name: in INSEE's Sirene directory, the legal name is simply RENAULT, with the legal form (SA) held in a separate field. VIES returns what the tax database holds, in its own wording, so don't expect an exact match with the register.
The same SIREN with a wrong key, FR02441639465. Invalid. The key (the two characters after FR) is computed from the SIREN, so a wrong key gives an invalid number, before anyone looks it up. See how to compute the key.
A Spanish company's number. Valid, but name and address came back as "---": Spain doesn't display them. You learn that the number is registered, not who holds it.
The errors you'll meet
VIES depends on each country's system. If that system is busy or down, you don't get "invalid", you get an error. On our first try for the French number, the answer was an error code, MS_MAX_CONCURRENT_REQ: the French service had too many requests at that moment. Five seconds later the same request worked.
So in your software:
- Never treat an error as "invalid". Retry later, and keep the customer's status as "not yet checked".
- Validate the format first. For French numbers, check the key against the SIREN locally: it removes most typing errors without a call.
- Space out retries, and don't hammer a busy country service.
What VIES doesn't tell you
- Whether the company is active in the register. A number can be registered for VAT while the register shows changes you'd want to know about. The register, not VIES, says whether a French company has ceased.
- Who the company is, in some countries. As our Spanish check shows, you may get "valid" and nothing else.
- The legal name as registered. Even when a name is returned, it's the tax database's version.
- Whether the person you deal with represents the company. No register answers that by itself.
For a French customer, the VAT number contains the SIREN, so you can go straight to the register: take the last nine digits, check that the company is active, and compare its legal name and address with your records. See how to check whether a French company is still active.
Checking numbers in your software
If you check VAT numbers inside a product, for example at checkout or when a customer adds billing details, a few rules keep the experience fair:
- Normalise first. Remove spaces and dots, upper-case the country prefix, and check the length and pattern for the country.
- Check the French key locally, so typing errors are caught on the form, before any call.
- Call VIES asynchronously where you can. If the country service is busy, let the customer continue and mark the number "pending".
- Show the result plainly: valid, invalid, or "couldn't be checked yet". Never turn an error into "invalid".
- Re-check periodically. A number valid at sign-up can stop being valid later.
Keep proof of each check
An invoice that relies on a customer's VAT number may be questioned years later. Keep a record of each check, and ask your tax adviser what your invoicing must show when a number is invalid.
A good record for each customer holds: the number checked, the answer (valid, invalid or error), the date, and the register check that goes with it.
When VIES and the register disagree
- VIES valid, register shows the company ceased. Stop and ask: a VAT number can outlive the activity for a while in a tax database.
- VIES invalid, register shows the company active. The company may not be registered for intra-Community trade, or the number may be mistyped. Ask the customer, and follow the tax rules for an invalid number.
- Names differ. Use the register's legal name on the contract, and keep both.
Fuentio's API will resolve a French VAT number to the company: legal name, status with its date and registered office, with the source and the check date. VIES stays the authority on VAT registration. The API isn't open yet: join the waitlist below to hear the day it opens.
For Spanish customers, see how to check a Spanish company before you sign. See what we cover in France and Spain.
Limits. VIES answers and errors are those we got on 9 October 2026; the descriptions quoted come from the European Commission and service-public.fr, read the same day. VIES says whether a number is registered for VAT; a register check says whether the company exists and is active. Fuentio doesn't check VAT registration. Not legal or tax advice.
Frequently asked questions
Does a valid VIES result prove the company is active?
No. It proves the number is registered in the national VAT database. Check the company register for its status.
Why does VIES show no name for some numbers?
Each country decides, under its data protection rules, whether to display the name and address. Spain didn't in our test.
What does MS_MAX_CONCURRENT_REQ mean?
The country's service had too many requests at that moment. Retry later; it isn't an "invalid" answer.
Can I get the SIREN from a French VAT number?
Yes: the last nine digits of a French VAT number are the SIREN.
Sources
- European Commission, VIES (checks run on 9 October 2026): ec.europa.eu
- European Commission, VIES FAQ: ec.europa.eu
- Service-public.fr, intra-community VAT number (page checked on 3 March 2025): entreprendre.service-public.gouv.fr
- Annuaire des Entreprises: annuaire-entreprises.data.gouv.fr