To check a VAT number online, use the European Commission’s free VIES portal for any number issued by an EU member state, and HMRC’s free lookup at gov.uk/check-uk-vat-number for a UK GB number. Both tools are free, return a result in seconds, and produce a page you can save as evidence of the check. Northern Ireland numbers that start with XI go through VIES; UK numbers that start with GB go through HMRC.
What You Need Before You Check
A VAT identification number begins with a two-letter country code and is followed by digits or a mix of digits and letters. Germany uses DE plus nine digits. France uses FR plus eleven characters that may include letters. Ireland uses eight or nine characters with one or two letters mixed in. Length and composition vary by country, so there is no single universal format beyond the country prefix.1Taxation and Customs Union. VAT Identification Numbers UK VAT numbers are nine digits, sometimes shown with a GB prefix.2GOV.UK. VAT Registration Number – HMRC Patterns for Services
You will usually find the number on an invoice, price quote, order confirmation, or business letterhead, near the seller’s address or in a tax-information block. Copy it exactly. A single wrong digit or missing letter returns an invalid result, and none of the official tools have fuzzy matching or a “did you mean” feature.
How to Verify an EU VAT Number Using VIES
The European Commission runs the VAT Information Exchange System, known as VIES. It looks like a database but is actually a search engine: it sends your query in real time to the relevant member state’s national VAT register and returns whatever that country’s tax authority reports back.3European Union. Check a VAT Number (VIES) That means VIES is only as current and available as the national system behind it.
To run a check, open the VIES portal, pick the member state from the dropdown (which handles the country prefix), enter the numeric portion of the number, and click verify. The system queries the national database live.
What comes back depends on the country. Some member states return the business name and registered address alongside a “valid” confirmation. Others, citing data-protection rules, will only confirm whether a particular name and address you supply match the number, without displaying the details independently.3European Union. Check a VAT Number (VIES) If you might need proof later for a tax audit, save or print the confirmation page. The Commission recommends keeping a record of every validation you run.
When VIES Shows a Member State as Unavailable
Because VIES pings national servers live, you will sometimes see a message that a member state’s service is unavailable. That does not mean the VAT number is invalid. It means the country’s database is offline for maintenance or having technical problems. Check the VIES self-monitoring page, which shows the real-time status of each country’s connection, and try again later.
How to Check a UK VAT Number
Since the UK left the EU’s VAT system, British numbers no longer appear in VIES. HMRC runs its own free lookup at gov.uk/check-uk-vat-number.4GOV.UK. Check a UK VAT Number Enter the nine-digit number and the tool returns the registered business name and address if the number is active. The results page itself is your record, so save or screenshot it with the date visible.
If you need auditable proof with a unique reference number, HMRC’s Check a UK VAT Number API offers a “verified check” mode that returns a reference number as formal proof a lookup happened. The API is a REST service with a simple check that confirms validity and returns the name and address, and a verified check that also generates the reference. Getting access takes time: you register through HMRC’s Software Developer Hub, test in a sandbox, and accept the Terms of Use before receiving production credentials. HMRC estimates around two weeks for the registration process. Version 2 of the API requires authentication; the unauthenticated version 1 was removed in February 2025.5GOV.UK. Check a UK VAT Number API
Northern Ireland and the XI Prefix
Northern Ireland sits in both systems. For trade in goods with the EU, Northern Ireland businesses use a VAT number that starts with XI instead of GB. A business with the standard UK number GB 123456789 uses XI 123456789 on invoices and documentation involving EU customers or suppliers.6GOV.UK. Register for VAT – Selling or Moving Goods Between Northern Ireland and the EU
An XI number is verified through VIES, since Northern Ireland remains aligned with EU VAT rules for goods. On the VIES portal, select “Northern Ireland (XI)” in the member state dropdown. A GB prefix goes to HMRC instead. Sending each prefix to the wrong tool is one of the more common verification mistakes in post-Brexit trade.
What to Do When a Number Comes Back Invalid
An invalid result does not always mean the business is fraudulent. The usual explanations are ordinary:
- A typo. One wrong digit or a missing character is enough. Compare the number character by character against the invoice.
- The wrong tool. A GB number checked in VIES, or an EU number checked on the HMRC site, will always fail. Match the prefix to the correct system.
- Database lag. A newly registered business may not appear immediately. National databases update on their own schedules.
- Member state downtime. If VIES reports that a country’s service is unavailable, the number is not invalid; the national system is temporarily offline.
- Deregistration. The business may have been deregistered, voluntarily or otherwise.
Ask the supplier to confirm the number and, if needed, send a copy of their VAT registration certificate. If the number still fails, contact the relevant national tax authority directly. HMRC can confirm whether a UK registration is pending or recently changed. For EU numbers, each member state’s tax administration handles its own register, and the VIES page links to contact details for each one. Do not proceed with the transaction while hoping the number sorts itself out. An unverified number leaves the tax liability with you if the supply turns out to involve an unregistered entity.
Why Verification Matters for Tax Deductions and Liability
The financial consequences of skipping the check are real. In the EU, zero-rating an intra-community supply of goods requires that both parties hold valid VAT identification numbers. If your customer’s number turns out to be invalid, the zero-rate treatment can be denied retroactively, and you owe the full VAT amount to your own tax authority with no way to collect it from the buyer after the fact.
In the UK, HMRC’s rules are equally strict. To deduct input tax you need a valid VAT invoice that complies with the invoicing regulations. If the supplier’s VAT number on that invoice is invalid, HMRC can refuse the deduction. For goods associated with known fraud risks, HMRC also applies a “reasonable steps” test: you must show you took genuine commercial steps to verify that your supplier and the supply were legitimate. Fail that test and you lose the input tax deduction even if you hold other evidence of the transaction.7GOV.UK. How to Treat Input Tax – Alternative Evidence for Claiming Input Tax
Beyond denied deductions, UK law allows HMRC to hold a buyer jointly and severally liable for VAT that a fraudulent supplier failed to pay to the government. The power is aimed primarily at missing-trader fraud chains, but the underlying principle is broader. A 30-second check is the cheapest form of protection available, and it can prevent a liability that dwarfs the cost of the goods themselves.