How to Check a Customer's EU VAT Number

You are about to invoice a business in another EU country without charging VAT, and you want to confirm their VAT number first. This guide walks through the check, what to keep as proof, and what to do when the answer is not a clean yes. No code involved.

What You Need Before You Check

Two things: the customer's VAT number exactly as it appears on their quote, contract or invoice, and the country it belongs to. The number starts with a two-letter country prefix (Greece uses EL, not GR). If a number arrives without a prefix, ask the customer which country it is registered in rather than guessing. The format guide shows what a number looks like in each country.

Check the Number Step by Step

1. Open the vatnode VAT number checker.
2. Paste the full number, including the country prefix.
3. Run the check and wait for the result.
4. Read the result and the date it shows. The result is the answer as of that moment, not a standing status.
5. Save the proof, as described below, before you issue the invoice.

The checker queries VIES, the European Commission's system that relays each request to the member state's own VAT register. What VIES is and how its country nodes work is covered in the VIES explainer.

Read the Result: Valid, Invalid or Could Not Be Checked

A valid result is evidence, not a verdict. Whether you can invoice without VAT depends on the transaction as well; the rules are in the reverse charge guide. This page is not legal or tax advice.

What to Record as Proof of the Check

An auditor asks one question: what did you know about this customer when you issued the invoice? Keep a record that answers it without anyone having to repeat the check:

• the VAT number as checked, with the country prefix
• the date and time of the check
• the result: valid or not valid
• the company name and address, if the check returned them
• the invoice or order the check belongs to
• the consultation number, if you obtained one
• any failed or unavailable attempts, with their times

VIES can also return a consultation number, a reference that documents who checked which number and when. It is tied to your own VAT number, so the public checker, which runs without one, does not issue it. If you need that reference on file, see what auditors look for in VAT documentation.

What to Do When the Number Is Invalid

1. Compare the number you entered with the customer's own document, character by character.
2. Check the country prefix. A wrong prefix or a mistyped digit is a frequent cause.
3. Check again. If it still fails, ask the customer to confirm the number and the country of registration.
4. Until the number is confirmed, do not apply the reverse charge or the intra-EU exemption on the strength of this number alone. For goods, a valid VAT number is a condition of the exemption; for services, other evidence of the customer's business status may be accepted, and the rules vary by country. Ask your tax adviser before invoicing without VAT. The risks of getting this wrong are in the invalid-number risk post.

What to Do When VIES Is Unavailable

A "could not be checked" result means the service did not answer, not that the number is wrong. Wait a few minutes and try again. Do not record the number as invalid, and do not record it as valid either. Note the failed attempt with its time, check again later, and finish the invoice once you have an answer. Mind your invoicing deadline: if it falls before VIES recovers, ask your tax adviser how to proceed. More on outages and how long they last is in the VIES downtime guide.

Checking by Hand or Automating It

Checking by hand works for a handful of customers. It stops working when you invoice many businesses, when numbers arrive through a signup or checkout form, or when you need the same record for every check. At that point, let your system run the checks: the vatnode API returns the result, the details and a check ID for each number, and the developer guide shows how to build it. For when to check in the first place, see when to validate customer VAT numbers.

Frequently Asked Questions