VIES VAT Number Checker

Verifying a business partner's VAT number is one of the most important due-diligence steps in cross-border trade across Ireland, the UK, and the wider European Union. A valid VAT number is what allows you to zero-rate intra-EU supplies (refer to our comprehensive VAT Rates Ireland guide to check rates), protect your input VAT reclaims, and demonstrate to Revenue or HMRC that you took reasonable steps to confirm who you were dealing with. Get it wrong and you risk rejected VAT claims, unexpected liabilities, and exposure to VAT fraud. This page's format validator instantly checks whether a VAT number is structured correctly for its country before you take the next step and confirm it against the official live databases. Below, we explain how VAT numbers are formatted, how to check Irish and UK numbers specifically, and how the EU's VIES system works.

What is a VAT Number?

A VAT number (VAT identification number) is a unique code issued to a business when it registers for Value-Added Tax. It identifies the business to the tax authorities and to its trading partners, and it must appear on VAT invoices so that customers can reclaim the tax and authorities can trace the supply chain.

Every EU VAT number follows a common pattern: a two-letter country code prefix followed by a national registration number of up to twelve characters, with the exact length and structure varying by country. A few examples illustrate the variety:

• Ireland (IE): IE followed by 7 digits and 1 or 2 letters (e.g. IE1234567A or IE1234567AB)
• Germany (DE): DE followed by 9 digits
• France (FR): FR followed by 2 characters and 9 digits
• United Kingdom (GB): GB followed by 9 digits (or 12 for branch traders)
• Northern Ireland (XI): XI followed by 9 digits, for goods trade with the EU

One frequent trap: Greece uses the prefix EL, not GR. Another is confusing the country code with the number itself — in official databases the country is selected from a dropdown and the number is entered without its prefix.

How to Check an Irish VAT Number

Checking an Irish VAT number is a two-stage process: first validate the format, then confirm the number is live and registered.

Step 1 — Format validation. An Irish VAT number begins with the IE prefix, followed by 7 numeric digits and 1 or 2 letters. Older-style numbers take the form of 7 digits plus one trailing letter (IE1234567A); newer numbers can include a second letter (IE1234567AB), and some formats include a "+" or "*" character in the second position. The validator on this page checks that the number you enter matches this expected pattern, catching typos and transposed characters instantly.

Step 2 — Live validation via VIES. A correct format does not prove the number is real or currently active. To confirm that, check the number against the official VIES database, which queries Ireland's Revenue records in real time. Select "Ireland (IE)" from the member-state dropdown, enter the number without the prefix, and VIES returns "valid" or "invalid" along with the business name and address where data-protection rules permit.

Keep a record — a screenshot or the VIES consultation number — as evidence that you checked, since the legal protection attaches to the date of the check.

UK VAT Number Validation (HMRC)

Since the UK left the EU, GB VAT numbers can no longer be checked on VIES. The European Commission removed the UK from VIES on 1 January 2021, so any GB number entered into VIES will simply return "invalid" — not because the business is unregistered, but because the UK is no longer in that system.

To validate a UK VAT number, use the official HMRC UK VAT number checker service on GOV.UK. A GB number is 9 digits (or 12 for branch traders); enter it without the GB prefix, and HMRC confirms whether the registration is valid and shows the registered business name and address. HMRC is now the authoritative registry for UK VAT.

Northern Ireland is the key exception. Under the Windsor Framework (formerly the Northern Ireland Protocol), Northern Ireland remains aligned with EU VAT rules for goods. NI businesses trading goods with the EU use an XI-prefixed VAT number, and — crucially — XI numbers remain checkable on VIES, not through HMRC. This means a single NI business may hold both a GB number (for UK domestic purposes and services) and an XI number (valid on VIES for goods trade with the EU). Choosing the right system for the prefix in front of you — GB to HMRC, XI to VIES — is one of the most common post-Brexit verification mistakes.

VIES VAT System Explained

VIES (the VAT Information Exchange System) is the European Commission's free, real-time tool for validating VAT numbers issued anywhere in the EU, plus Northern Ireland (XI) numbers for goods. Rather than holding one central list, VIES acts as a search engine that queries each member state's own national VAT database at the moment you make the request, returning a live "valid" or "invalid" result.

VIES is established under Council Regulation (EU) 904/2010 on administrative cooperation in the field of VAT, which legally obliges each member state to maintain an accurate, queryable registry of its VAT-registered traders (if your business has recently crossed thresholds requiring registration, review our VAT Thresholds Ireland guide). When you run a check, VIES can issue a consultation number — a reference with evidentiary value across all 27 member states that proves you verified the number on a specific date. This matters for international reporting: a valid customer VAT number is the basis for zero-rating intra-EU supplies of goods and for the associated recapitulative statements (EC Sales Lists) that businesses file to report those cross-border transactions.

Because VAT status can change from day to day, a check protects you only for the date it was made — validating once and relying on the result indefinitely is not sufficient for ongoing trading relationships.

Frequently Asked Questions