How to Check If a Company Is VAT Registered UK

This is a question I deal with constantly, both from business owners and from individuals who simply want reassurance before paying an invoice. Knowing whether a company is VAT registered is not just a box-ticking exercise. It directly affects whether VAT should be charged, whether you can reclaim VAT, and whether an invoice is actually compliant with UK tax law.

In this guide I will walk you through how to check if a company is VAT registered, why it matters, what the results really mean, and the common traps I see in practice. I will explain this from a UK perspective, using current guidance and real world experience from working with VAT registered businesses and HMRC queries. Everything here reflects how VAT is actually applied and checked in day-to-day UK business life.

Why it matters if a company is VAT registered

Before getting into the mechanics of how to check, it is important to understand why this matters in the first place.

Whether a company is VAT registered affects:

Whether they are allowed to charge VAT

Whether you are allowed to reclaim VAT

Whether an invoice is valid for VAT purposes

How much you should expect to pay

Whether there is a potential compliance issue

In my experience, many VAT problems start with assumptions. People assume a company must be VAT registered because it looks professional, or because it is a limited company, or because it charges VAT on its invoice. None of those assumptions are reliable.

The only thing that proves VAT registration is confirmation through official records.

What VAT registration actually means

A company that is VAT registered has been issued with a VAT registration number by HM Revenue & Customs.

This means:

They are registered for VAT in the UK

They are entitled to charge VAT on taxable supplies

They must submit VAT returns

They must follow UK VAT invoicing rules

It does not necessarily mean they are profitable, large, or well run. It simply means they have either exceeded the VAT registration threshold, chosen to register voluntarily, or are required to register for another reason.

What a UK VAT number looks like

Understanding what a VAT number looks like helps you spot obvious issues.

A UK VAT registration number usually:

Starts with the letters GB

Is followed by nine digits

May include an additional three digit branch identifier

For example, GB123456789.

If a company provides a number that does not match this format, that should immediately prompt further checks.

The simplest way to check if a company is VAT registered

The easiest and most reliable way to check VAT registration is to use the official HMRC VAT checker.

HMRC provides a free online service that allows you to:

Check if a VAT number is valid

Confirm the business name linked to that number

Verify whether the number is currently active

This is the same system HMRC expects businesses to use when carrying out basic VAT due diligence.

I regularly advise clients to use this checker when onboarding new suppliers or customers, especially if VAT is involved.

What information you need to carry out a VAT check

To check VAT registration properly, you usually need at least one of the following:

The company’s VAT registration number

The company’s legal name

The company’s trading name

If you only have a business name and no VAT number, the process becomes less direct, but it is still possible to investigate further.

Checking a VAT number using HMRC’s online tool

When you enter a VAT number into the HMRC checker, the system will return one of several outcomes.

If the VAT number is valid

If the number is valid, HMRC will usually confirm:

That the number exists

That it is currently active

The business name associated with it

This confirmation is important. The name returned should broadly match the company you are dealing with. Small differences can occur due to trading names, but significant mismatches are a warning sign.

If the VAT number is invalid

If the VAT number is invalid, this could mean:

The number does not exist

The number has been typed incorrectly

The company is not VAT registered

The registration has been cancelled

In this situation, you should not accept VAT charged on the invoice until the issue is clarified.

What if you do not have a VAT number

Sometimes a supplier has not provided a VAT number, but you suspect they may be VAT registered.

In this case, ask yourself:

Does the invoice show VAT separately

Does it state a VAT rate

Does it say “VAT included” or “plus VAT”

Is there any reference to VAT at all

If VAT is being charged, the supplier must provide a VAT registration number. There is no exception to this rule for standard VAT invoices.

If they cannot provide one, they should not be charging VAT.

Using Companies House as a secondary check

Companies House does not show VAT registration status directly, but it can still be useful.

You can use Companies House to:

Confirm the company’s legal name

Confirm its registration number

Check whether it is active or dissolved

Compare invoice details to official records

If an invoice shows a company name that does not match Companies House records, that is another red flag.

VAT registration and trading names

One area that causes confusion is trading names.

A company may:

Be legally registered under one name

Trade under a different business name

Use branding that does not match its legal name

This is allowed, but VAT registration is always linked to the legal entity, not the trading name.

When you check a VAT number, the name returned may not exactly match the trading name on the invoice. This is acceptable as long as the underlying legal entity is correct.

What if the VAT number belongs to a different company

This is a serious issue.

If a VAT number belongs to a different legal entity, it may indicate:

An invoicing error

A misunderstanding within the supplier’s business

Incorrect use of a group VAT number

In the worst cases, VAT fraud

If the VAT number does not match the company issuing the invoice, you should not reclaim VAT until the situation is resolved.

HMRC expects businesses to take reasonable steps to verify VAT numbers, especially where VAT is reclaimed.

Group VAT registration and how it affects checks

Some companies are part of a VAT group.

In a VAT group:

One VAT number covers multiple companies

Invoices may be issued by different group members

The VAT number belongs to the group representative

When checking a group VAT number, the name returned may be the group company, not the individual trading entity.

This is not automatically a problem, but it should make sense commercially.

Checking VAT registration for overseas companies

If a company is based overseas, the position changes.

Key points to understand:

Overseas companies may be VAT registered in the UK

UK VAT numbers still start with GB

EU VAT numbers follow different formats

Non UK VAT may not be reclaimable in the UK

If an overseas company charges UK VAT, they must have a valid UK VAT registration number. This can be checked using the same HMRC system.

Why VAT registration status can change

VAT registration is not permanent.

A company may:

Register for VAT

Deregister later

Be forcibly deregistered

Change legal structure

This means a VAT number that was valid in the past may no longer be valid now.

For this reason, checking VAT registration should not be a one-off exercise. It should be done periodically, especially for regular suppliers.

Common mistakes I see when checking VAT registration

These issues come up repeatedly in practice:

Assuming limited companies are always VAT registered

Reclaiming VAT without checking the VAT number

Accepting invoices that say “VAT included” but show no VAT number

Not checking whether a VAT number is still active

Assuming a long-standing supplier must still be registered

Most of these mistakes are understandable, but HMRC still expects corrections if VAT is reclaimed incorrectly.

What happens if you reclaim VAT from a non VAT registered company

If you reclaim VAT that was not validly charged, HMRC can:

Disallow the VAT reclaim

Charge interest

Apply penalties for careless errors

HMRC will not pursue the supplier on your behalf. The responsibility sits with the business reclaiming the VAT.

This is why checking VAT registration is not optional, it is part of proper VAT control.

What to do if you discover a problem

If you discover that a company is not VAT registered but has charged VAT, act quickly.

You should:

Contact the supplier

Ask for clarification or a corrected invoice

Request a refund of incorrectly charged VAT

Amend your VAT return if necessary

Leaving the issue unresolved can cause bigger problems later, particularly during a VAT inspection.

Best practice for checking VAT registration

Based on real world experience, I recommend the following approach:

Always check VAT numbers for new suppliers

Recheck periodically for key suppliers

Keep evidence of VAT checks

Train staff who process invoices

Question anything that does not look right

Good VAT compliance is built on habits, not firefighting.

Final thoughts on checking VAT registration

Checking whether a company is VAT registered is one of the simplest yet most important VAT controls you can put in place. It protects you from reclaiming VAT you are not entitled to, it reduces the risk of HMRC penalties, and it gives you confidence that your records are correct.

VAT problems often start with small assumptions, and grow because no one stops to verify the basics. Taking a few minutes to check VAT registration can save months of stress later.

If VAT is a regular part of your business, treating VAT checks as standard procedure rather than an afterthought is one of the smartest compliance decisions you can make.