Can I check a UK VAT number in VIES?

Not a Great Britain (“GB”) number — it is no longer in VIES since Brexit. Use HMRC's “Check a UK VAT number”. A Northern Ireland “XI” number (for goods) can still be checked in VIES.

What is HMRC's “Check a UK VAT number” service?

A free GOV.UK service that confirms whether a UK VAT number is valid and shows the registered business name and address. If you are UK VAT-registered, it can also record a dated proof that you checked.

How many digits does a UK VAT number have?

Usually 9 digits, shown with the “GB” prefix; some larger organisations use a 12-digit format with a 3-digit branch suffix. Enter the digits without spaces.

The VAT number is valid but registered to a different name — is that a problem?

It is a reason to pause. The HMRC service shows the registered name and address; if they do not match your counterparty's invoice, clarify before you proceed — it can indicate an error, a group structure or an attempt to misuse someone else's number.

Should I keep proof that I checked a VAT number?

Yes. Keep a dated record — HMRC's service can provide a reference for UK VAT-registered users, and for EU numbers keep the VIES confirmation. It documents your diligence if a tax authority questions the transaction later.

Is a UK VAT number the same as the company number?

No, they are two different things. The company number (CRN) is 8 characters from Companies House and confirms the company legally exists; the VAT number is separate, issued by HMRC for tax. To check the company itself, see our guide on how to check a UK company.

How to check a UK VAT number after Brexit (VIES vs HMRC)

Published: 2026-07-22

To check a UK VAT number after Brexit, use HMRC's free “Check a UK VAT number” service — not the EU's VIES, which no longer holds Great Britain VAT numbers. The one exception is Northern Ireland: for goods, NI businesses use a VAT number with the “XI” prefix, and those numbers can still be checked in VIES. Below we explain why this changed, how to verify a UK VAT number step by step, the common mistakes to avoid, and what evidence to keep. Getting this right matters: an invalid or mismatched VAT number can put the tax treatment of your invoice in doubt. This is general information, not tax advice.

Why is a UK VAT number no longer in VIES?

VIES (the VAT Information Exchange System) is an EU tool that lets you validate the VAT numbers of businesses registered in EU member states. When the UK left the EU and the transition period ended, Great Britain (England, Scotland and Wales) left the EU VAT system for this purpose — so GB VAT numbers were removed from VIES.

This is not a sign that anything is wrong with a UK company. A perfectly legitimate, VAT-registered British business simply cannot be validated in VIES anymore, because VIES only covers EU (and Northern Ireland, for goods) registrations. Trying to check a GB number there and getting “not found” is expected behaviour, not a red flag. The correct tool is HMRC's own service.

How do I check a UK VAT number with HMRC?

HMRC provides a free online service called “Check a UK VAT number”. You enter the number, and the service confirms whether it is valid and shows the name and address of the business registered for it. According to GOV.UK, if you are UK VAT-registered yourself, the service can also record proof that you checked a number on a given date — a reference you can keep in case a tax authority later asks.

A UK VAT number is usually 9 digits, shown with the “GB” prefix (for example GB followed by 9 digits); some larger organisations have a 12-digit format with a branch suffix. Enter the digits without spaces. Match the name and address the service returns against what the counterparty put on their invoice — a valid number registered to a different name is a reason to pause and ask questions.

The Northern Ireland exception: “XI” VAT numbers

Northern Ireland is a special case. Under the Northern Ireland Protocol (as amended by the Windsor Framework), NI remains aligned with EU rules for trade in goods. To make that work, NI businesses trading goods with the EU use a VAT number with the “XI” prefix instead of “GB”. According to GOV.UK, these XI numbers can be validated in VIES, just like an EU number.

So the rule of thumb is: a “GB” number is checked at HMRC; an “XI” number can be checked in VIES. The distinction mainly concerns goods — the treatment of services can differ. If your transaction involves Northern Ireland or you are unsure which applies, this is exactly the kind of question to confirm with HMRC or a tax adviser rather than guess.

Which tool to use for which VAT number (source: GOV.UK, European Commission)
VAT number	Where to check	In VIES?
GB + 9 digits (Great Britain)	HMRC “Check a UK VAT number”	no
XI + digits (Northern Ireland, goods)	VIES (or HMRC)	yes
EU number (e.g. SE, DE, PL)	VIES	yes

Why verify a VAT number at all?

A VAT number is more than an administrative detail. Confirming it is valid and belongs to your counterparty supports the correct VAT treatment of a cross-border transaction and is part of the due diligence tax authorities expect. An invalid, expired or mismatched number can put the tax treatment of your invoice in doubt and, in the worst case, leave you exposed if the counterparty turns out to be fraudulent.

It is also a simple fraud filter. Criminals sometimes quote a real, valid VAT number that belongs to a genuine business — but on an invoice where the bank details lead somewhere else. Checking the number and matching the registered name and address is a quick way to notice when the number and the party do not line up. The check takes a minute and costs nothing; the consequences of skipping it can be expensive.

Common mistakes when checking a UK VAT number

Four mistakes come up again and again. First, panicking when a “GB” number is “not found” in VIES — that is expected after Brexit; use HMRC instead. Second, confusing the VAT number with the company number (CRN): they are different identifiers issued by different bodies. Third, treating a valid number as the end of the check and ignoring that it is registered to a different name or address than the one on the invoice. Fourth, forgetting to keep a dated record of the check.

A fifth, subtler one: assuming that because a number checks out, the VAT treatment of your deal is automatically correct. Verification tells you the number is real and whose it is — not how to invoice or account for the transaction. Keep those two questions separate: verify the number here, and settle the VAT treatment with HMRC, your tax authority or an adviser.

When should you re-check a VAT number?

A VAT registration is not permanent — a business can deregister, or have its registration cancelled, so a number that was valid last year is not guaranteed to be valid today. For a one-off transaction, checking once at the time is enough. For an ongoing relationship, it is worth re-checking periodically and before any large invoice.

A practical rule: verify at the start of the relationship, again before a significant payment or a change in terms, and keep each dated result. This mirrors what you already do with the company register — verification is a moment-in-time snapshot, so for anything that matters, take a fresh snapshot rather than relying on an old one.

What does this mean for your invoices and VAT?

This article is about verification — confirming that a VAT number is valid and belongs to your counterparty. How you then treat VAT on a cross-border transaction (for example whether a reverse charge applies, or how goods versus services are handled after Brexit) depends on your own country's rules, the nature of the supply and your VAT status. Those rules changed with Brexit and are genuinely technical, so we do not give a one-size-fits-all answer here.

What we can say plainly: keep a dated record of every VAT check, because tax authorities expect you to have verified your counterparty; match the registered name and address to the invoice; and when the VAT treatment itself is in doubt, confirm it with HMRC, your national tax authority, or a tax adviser. Getting the verification right is the part you fully control — it takes a minute, it is free, and it is the foundation for everything that follows.

Frequently asked questions

Can I check a UK VAT number in VIES?: Not a Great Britain (“GB”) number — it is no longer in VIES since Brexit. Use HMRC's “Check a UK VAT number”. A Northern Ireland “XI” number (for goods) can still be checked in VIES.
What is HMRC's “Check a UK VAT number” service?: A free GOV.UK service that confirms whether a UK VAT number is valid and shows the registered business name and address. If you are UK VAT-registered, it can also record a dated proof that you checked.
How many digits does a UK VAT number have?: Usually 9 digits, shown with the “GB” prefix; some larger organisations use a 12-digit format with a 3-digit branch suffix. Enter the digits without spaces.
The VAT number is valid but registered to a different name — is that a problem?: It is a reason to pause. The HMRC service shows the registered name and address; if they do not match your counterparty's invoice, clarify before you proceed — it can indicate an error, a group structure or an attempt to misuse someone else's number.
Should I keep proof that I checked a VAT number?: Yes. Keep a dated record — HMRC's service can provide a reference for UK VAT-registered users, and for EU numbers keep the VIES confirmation. It documents your diligence if a tax authority questions the transaction later.
Is a UK VAT number the same as the company number?: No, they are two different things. The company number (CRN) is 8 characters from Companies House and confirms the company legally exists; the VAT number is separate, issued by HMRC for tax. To check the company itself, see our guide on how to check a UK company.

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This guide is for information purposes only and does not constitute legal or tax advice. Laws and registry rules may change — the information held in the relevant country's official registers is always decisive.