How to verify a UK VAT number online
Every B2B business in Britain handles invoices stamped with a GB VAT number. Before you approve payment, issue a zero-rated invoice, or add a supplier to your accounts, you need proof the registration is genuine. This guide shows you how to verify a UK VAT number online using HMRC's official registry — free, fast, and without creating an account.
Step 1: Locate the VAT number on the invoice
Start with the document in front of you. A legitimate UK supplier should display their UK VAT number on every tax invoice, quote, and contract. Look for a code starting with GB followed by nine digits — for example GB116300129. If the number is missing, buried in fine print, or formatted differently from standard HMRC rules, treat that as a red flag and investigate before you pay.
Step 2: Confirm the GB VAT number format
Most registrations follow GB plus nine digits; some VAT groups use 12. Remove spaces and hyphens before you search. If the prefix is wrong, the length does not match, or the supplier claims to be UK-registered but quotes an IE or DE number instead, pause and run a UK VAT number check only after you have the correct identifier. Our UK VAT numbers guide covers format rules and common mistakes finance teams see on incoming paperwork.
Step 3: Run an HMRC VAT check online
Since Brexit, GB numbers are validated through HMRC — not the EU VIES system. Open a trusted HMRC VAT check online service, enter the full number including the GB prefix, and submit. Use our free UK VAT checker for instant official results, or read how VAT validation works for a deeper breakdown. See also how to verify a VAT number online in the UK for related guidance.
Step 4: Read and record the verification result
A successful GB VAT number verification confirms whether the registration is valid and returns the business name and address HMRC holds on file. Compare those details to your supplier — if they do not match, contact them before paying. When the status shows invalid, do not proceed. See why you should verify VAT numbers before every B2B transaction.
When should you verify a UK VAT number?
Build a validate UK VAT number HMRC step into supplier onboarding, accounts payable, and high-value invoice approval. Keep a dated record of each UK supplier VAT check for audit trails. Country-specific tips are in our FAQ.
UK verification vs EU VIES checks
Numbers starting with GB must always go through HMRC. If you also trade with suppliers in EU member states, you will need VIES validation for those prefixes instead. Trading across both markets means keeping two workflows: one for check VAT number UK free via HMRC, and one for EU lookups. Read EU VAT numbers explained for formats, country codes, and intracommunity B2B rules.
Verify a UK VAT number now
Whether you are a small business owner, bookkeeper, or finance manager, knowing how to verify a UK VAT number online protects you from invoice fraud and supports clean compliance records. Visit the Check VAT Number homepage, enter the full GB number, and get instant HMRC results — or explore more articles on our blog.