EU VAT Number Validator

Why the check belongs at the start of the invoicing process

For tax-exempt intra-community B2B supplies or cross-border services within the European Union, verifying the recipient VAT identification number is mandatory. Every EU member state uses its own country prefix followed by a specific alphanumeric structure. If you invoice net against a VAT ID that turns out to be wrong, the VAT usually ends up on your side of the ledger — so the check belongs before the invoice goes out, not in the year-end clean-up.

Format patterns of the main trading countries

The example numbers are illustrative placeholders. The validator holds the patterns for all 27 EU member states plus the United Kingdom, detects the country automatically from the prefix, and strips spaces, dots, hyphens and slashes from whatever you paste in. Greek numbers are accepted with either the EL or the GR prefix.

Syntax validation is not a qualified VIES confirmation

Format and syntax validation is the structural first step. It answers exactly one question: is this string built the way the issuing country specifies? It says nothing about whether the number has actually been issued, is still active, or belongs to the company your customer named. That is what a confirmation request in the European Commission VIES system does — in Germany, the equivalent request runs through the Federal Central Tax Office. A simple request confirms that the number is valid; a qualified request additionally confirms the holder's name, town and address. Only that result is worth filing as evidence against the customer record.

This tool covers the first two steps: it checks the format, and at the press of a button it runs the simple confirmation request against VIES. When a member state's register does not answer — which happens regularly — the tool says exactly that instead of calling the number invalid. VIES returns a negative result together with an error code during an outage, and reading only the negative result is how you end up declaring a real company's VAT ID wrong.

Step by step: a B2B invoice from Germany to France

1. The customer enters FR XX 123 456 789 at checkout.
2. You paste the number into the field above — separators are removed and France is detected automatically.
3. A valid-format result means the structure is plausible. A red result should be resolved with the customer before the invoice is issued; typically a digit is missing or the prefix was dropped.
4. One click on “Check with VIES now” asks the European Commission's system whether the number is issued and active. Store the result together with the date. As evidence under § 18e UStG, add the qualified confirmation from the German Federal Central Tax Office.
5. Only then do you invoice net with a reverse-charge reference and report the turnover in your EC Sales List.
6. If the buyer is a private consumer, or the confirmation fails, you charge the destination country's VAT rate instead. Our article on VAT in e-commerce explains the mechanics, and the VAT Calculator gives you the gross/net split for the rate you land on.

Common pitfalls

• A national tax number is not a VAT ID — both exist in parallel and look different.
• The Austrian pattern most often loses the U right after the prefix.
• The United Kingdom is no longer part of VIES, so the tool checks GB numbers for format only.
• Customers change legal form or address, and numbers get deactivated. A VAT ID confirmed once does not stay valid forever, so recheck recurring B2B customers on a routine — ideally bundled into the month-end close. Our feature overview shows how invoices, payouts and master data are pulled together for that.

This tool is a free orientation aid, not tax advice. The binding assessment of your outgoing invoices and your evidence obligations belongs with your tax advisor.