VAT Number In UK 2026: How to Find, Format & Example

Register a business for VAT and HMRC hands it a unique VAT registration number. You must include it on invoices you raise. Other businesses can use HMRC’s online service to check whether a UK VAT registration number is valid. This guide walks through the number formats, how registration works, and how to check a supplier’s VAT registration number.

Key Takeaways

• A UK VAT number is normally nine digits led by GB, like GB123456789.
• Where HMRC has flagged a VAT-registered business as trading under the Windsor Framework, it has to put the XI prefix in front of its usual VAT number.
• There's no separate application. Your VAT number arrives automatically once registration is approved.
• If you want to check one, HMRC's free online checker confirms whether any UK VAT number is genuine.
• Don't confuse it with your company number, UTR, or National Insurance number. They're all different systems.

What is a VAT Number in UK?

When you register a business for VAT in the UK, HMRC gives it a unique reference — sometimes called a value-added tax number. People also call it a VAT registration number, a VAT ID, or a VAT ID no. The name doesn’t matter; it’s the thing that identifies your business on invoices, returns, and everything else you handle with HMRC.

VAT Number Format & Examples

There's nothing complicated about a GB VAT number's format. Nine digits, usually written with GB stuck on the front.

Those final two digits aren't arbitrary. A set formula derives them from the first seven, which means an invented number tends to fail before anyone even bothers looking it up. Brexit changed something else too: GB numbers dropped off the EU's VIES system entirely. VIES can validate XI VAT numbers for Northern Irish businesses covered by the Windsor Framework when they trade in relevant goods.

It's worth distinguishing a VAT number from other business references too. Your EORI number, used for customs, is often your VAT number with GB in front and 000 at the end, which is exactly why the two get confused. Your Unique Taxpayer Reference and your Companies House company number are different again, issued by different bodies for different purposes. None of these is interchangeable with your VAT number.

How to Get a VAT Number in UK (Registration): Step by Step Guide

There's no standalone application form here. Your VAT number simply arrives once your VAT registration clears.

Step 1: Check whether you need to register: You have to register once your taxable turnover tops £90,000 over the last 12 months, or you expect it to pass £90,000 within the next 30 days. You can also register voluntarily if your turnover is below this threshold.

Step 2: Gather your details: You'll need your business bank details, your Unique Taxpayer Reference, and your company registration number if you're a limited company.

Step 3: Register online: Sign in to your Government Gateway account and complete the VAT registration on GOV.UK. (Some VAT registrations must be made by post.)

Step 4: Wait for HMRC: If you have not received a response after 40 working days, contact the VAT Registration Service. Some applications may take longer.

Step 5: Receive your VAT number: After approval, HMRC sends you a VAT registration certificate. It lists your new VAT number, your effective date of registration, and the due date for your first return.

From there, get your VAT number onto your invoices without delay. Once registered, every VAT invoice you issue is required to carry it.

How to Find a Company VAT Number?

Start with the obvious place: a supplier's own invoice. Any VAT-registered business has to display its VAT number on that invoice, usually tucked in with the rest of its business details.

No invoice handy? A few other places to look:

• The company’s own website — often down in the footer, or on a "terms" or "about" page.
• Companies House, though it lists company numbers rather than VAT numbers directly, so check any filed documents.
• HMRC's free VAT number checker on GOV.UK — enter a number and it confirms whether it’s valid, and shows the registered business name and address.

Can I find a VAT number from a company name?

Not directly. HMRC's checker needs the VAT number itself, so there's no official search that works the other way round. Your best options are asking the business directly, checking their invoices or website, or reviewing Companies House filings that may reference it. Some private lookup tools claim to search by name, but always confirm any result against HMRC's own checker before relying on it.

It's worth checking a supplier's VAT number before you rely on it, particularly with a new or unfamiliar business. If you reclaim input VAT on an invoice showing a fake or invalid VAT number, HMRC can refuse the claim, and the cost falls on you rather than the supplier. The check takes under a minute and gives you a record that shows you carried out reasonable due diligence.

Conclusion

A UK VAT number usually has nine digits and is shown with a GB prefix. If HMRC identifies a business as trading under the Windsor Framework, it uses an XI prefix for relevant goods transactions with EU customers or suppliers. You don't apply for it separately, since it arrives automatically once your VAT registration is approved. If you ever need to confirm someone else's number, HMRC's free checker on GOV.UK is the quickest and most reliable way to do it.