How can I verify a VAT number online in the UK?
If you trade B2B in Britain, you will see a UK VAT number on almost every commercial invoice. Before you approve payment, apply zero-rated VAT, or onboard a new supplier, you should confirm that the GB VAT number is real and currently registered with HM Revenue & Customs (HMRC). The good news: you can verify a VAT number online in the UK in seconds, with no account required.
What does a UK VAT number look like?
Most active registrations use the prefix GB followed by nine digits — for example GB116300129. Some VAT groups use 12 digits. The number should appear on official invoices, contracts, and HMRC correspondence. If a supplier sends a tax ID without GB, or the length looks wrong, treat that as a warning sign and run a UK VAT lookup before you rely on it. Our guide to UK VAT numbers explains format rules in more detail.
How to verify a UK VAT number online
Since Brexit, GB numbers are checked through HMRC's registry, not the EU VIES system. Use a dedicated VAT checker UK tool that sends a live query to HMRC — enter the full number with the GB prefix and get an instant valid or invalid status. Try our free UK VAT checker or read how VAT validation works for a step-by-step guide to an online VAT number check UK businesses use for due diligence.
What you get from an HMRC VAT verification
A successful HMRC VAT check confirms whether the registration is active right now, plus the registered business name and address on HMRC's records. Matching that data to your supplier helps prevent invoice fraud. If the result is invalid, pause before paying — see why you should verify VAT numbers before every B2B transaction.
When should you check a UK VAT number?
Run a check UK VAT number lookup when onboarding a new supplier, reviewing a high-value invoice, or confirming a customer before a cross-border B2B sale. Many businesses build a quick GB VAT validation step into accounts payable so every payment is backed by an official record. Country-specific tips — including Ireland and other EU member states — are in our FAQ.
UK checks vs EU VIES validation
Numbers starting with GB must be verified through HMRC. For suppliers in EU member states, use VIES instead. If you trade across both markets, keep both workflows in mind: EU VAT numbers explained covers prefixes, formats, and intracommunity B2B rules for the 27 EU countries.
Verify a UK VAT number now
Whether you need to verify a supplier VAT number or confirm a customer before invoicing, an HMRC VAT verification takes seconds and costs nothing. Visit the Check VAT Number homepage and enter the full GB number — or browse more guides on our blog.