How to Find a Company's VAT Number & Check It's Valid

What a UK VAT number looks like

A UK VAT registration number is made up of the prefix "GB" followed by nine digits, for example GB123456789. You will sometimes see it written without the GB prefix, or with the digits grouped as 123 4567 89 for readability. Branch traders may have a twelve-digit version, and government departments and health authorities use slightly different formats. The important thing to remember is that a standard business VAT number is GB plus nine numbers — anything wildly different should make you pause. A VAT number is completely separate from a company registration number issued by Companies House, so do not confuse the two.

Where to find a company's VAT number

The most reliable place to find a VAT number is on an invoice or receipt. Any VAT-registered business is legally required to show its VAT number on the invoices it issues, usually near the top or in the footer alongside the company address. Many businesses also display their VAT number in the footer of their website, on their terms and conditions page, or on official quotations and order confirmations. If you cannot find it anywhere, the simplest approach is to ask the trader directly — a legitimate registered business will have no problem providing it. Bear in mind that not every company is VAT-registered: only businesses above the registration threshold, or those that have registered voluntarily, will have a VAT number at all.

Why VAT numbers are not on Companies House

VAT is administered by HM Revenue & Customs, not by Companies House, so you will not find a VAT number on the public Companies House register. Companies House holds incorporation details, registered office addresses, directors, and filed accounts, but VAT registration is a separate matter handled entirely by HMRC. This is a common point of confusion. If you want to research a company's wider details, you can still check a company on Companies House and review its filed accounts — just remember the VAT number itself comes from a different source.

Checking a VAT number is valid

To confirm a UK VAT number is genuine, use HMRC's free online VAT number checker. You enter the number and it tells you whether it is valid and shows the registered business name and address, which you can cross-check against the details on the invoice. For VAT numbers issued in the European Union, use the EU VIES system (VAT Information Exchange System), which validates numbers across member states. Both tools are free and take only a moment. If you are reclaiming VAT, it is good practice to keep a record of the validation result, including the date you checked, in case HMRC ever queries the claim.

What to do if a number looks fake

If a VAT number fails validation, or the registered name and address returned by the checker do not match the business you are dealing with, treat it as a warning sign. Sometimes it is an innocent typo, so re-enter the number carefully before drawing conclusions. If it still does not check out, do not pay any VAT element on the invoice and raise it with the supplier in writing. A business that cannot produce a valid VAT number but still charges you VAT may be acting fraudulently, and you should not attempt to reclaim VAT against an invalid number. You can report suspected VAT fraud to HMRC directly.

Why a valid VAT number matters

If your own business is VAT-registered, you can normally reclaim the VAT you pay to suppliers — but only when you hold a valid VAT invoice showing a genuine VAT number. Reclaiming against an invalid or fake number can leave you out of pocket if HMRC disallows the claim, and you may have to repay it. Verifying VAT numbers before you trade with a new supplier is a simple habit that protects your cash flow and your records. If you are building a list of suppliers or prospects to vet in bulk, our lead lists can help you organise and research businesses efficiently. For more research guides, head back to the BizLookup homepage.