Use the free HMRC checker at gov.uk/check-uk-vat-number. Enter the nine-digit VAT number, and it tells you whether the number is valid and which business it belongs to.
That takes about fifteen seconds. The rest of this page covers what the checker will not do, how to check EU numbers, and why an invalid supplier VAT number is your problem rather than theirs.
The GOV.UK VAT number checker
HMRC’s “Check a UK VAT number” service confirms two things:
- whether a UK VAT registration number is valid
- the name and address the number is registered to
It is free, it needs no login, and it works for anyone — customer, supplier, or curious member of the public.
You need the number before you start. The service cannot search by company name. If you do not have the VAT number, look on the supplier’s invoice, receipt, quotation, website footer or terms and conditions. A VAT-registered business is required to quote its number on the invoices it raises for taxable supplies, so a genuine VAT invoice will always show it.
Proving when you checked
There is a second mode most people miss. If your own business is VAT registered, you can enter your VAT number alongside the one you are checking and HMRC will record the check.
That gives you dated evidence that you verified a supplier’s number on a particular day. If the number later turns out to be invalid or hijacked, that record supports your position. For anyone dealing with new suppliers, unfamiliar subcontractors or large one-off purchases, it is worth the extra ten seconds.
What the checker will not tell you
| Question | Can the checker answer it? |
|---|---|
| Is this VAT number valid? | Yes |
| Who is it registered to? | Yes, name and address |
| Is company X VAT registered? | No — you cannot search by name |
| Was the number valid last March? | No, it checks current status only |
| Is this business solvent or trading? | No |
If you need to know whether a business is VAT registered and you do not have a number, there is no public register to search. Ask them. Any legitimate VAT-registered business will give you the number without hesitation.
Checking an EU VAT number
The GOV.UK checker only covers UK numbers. For a business in an EU member state, use the European Commission’s VAT Information Exchange System (VIES) at ec.europa.eu/taxation_customs/vies.
VIES validates numbers for all EU member states, and confirms the trader’s name and address where the member state releases that data. Some countries return validity only.
Northern Ireland numbers matter here. Under the Northern Ireland arrangements, businesses moving goods to and from the EU use an XI-prefixed number, and those are checked through VIES rather than the UK service. Great Britain numbers with a GB prefix are not on VIES.
What a UK VAT number looks like
A UK VAT registration number is nine digits, issued when the business registers and kept until the registration is cancelled or transferred to a new owner.
You will see it written several ways, all of them the same number:
123456789GB123456789GB 123 4567 89
The GB prefix is a country code used for cross-border trade, not part of the number itself. Spacing is presentational. Strip both before you check.
Some VAT-registered entities have longer variants — government departments and health authorities use a three-digit suffix, and branch traders can carry a twelve-digit format. Those are unusual, and if you meet one on an invoice it is worth asking about.
A number that is not nine digits, or that contains letters after the GB, is not a standard UK VAT number. That alone is enough to pause and ask.
What to do if a supplier’s VAT number is invalid
Do not assume fraud. The most common explanations are dull.
- Check for a typing error. Transposed digits are the usual cause. Compare against the invoice character by character.
- Check you are using the right checker. GB numbers go through GOV.UK, XI and EU numbers through VIES.
- Ask the supplier directly. They may have recently registered and be trading before HMRC has issued the number, they may have given you an old number after a change of legal entity, or the registration may have been cancelled.
- Ask for a corrected VAT invoice. If they are registered, a valid invoice showing the correct number is a reasonable thing to request.
- Withhold the VAT element until it is resolved if the amount is significant. Paying VAT to a business that is not registered means paying money that will never reach HMRC and that you will not be able to reclaim.
If a supplier will not or cannot produce a valid number, treat the VAT on their invoice as not chargeable. They should not be charging it.
Why this matters: your input VAT reclaim
Here is the part that costs money. To reclaim VAT on a purchase you must hold a valid VAT invoice, and a valid VAT invoice must show the supplier’s VAT registration number.
If the number is wrong, missing or belongs to a business that was not registered at the time of supply, HMRC can refuse the claim. You will have paid the 20% and be unable to recover it. Where the transaction turns out to be connected to VAT fraud and HMRC concludes you should have known, the consequences go further than a disallowed reclaim.
The exposure is entirely one-sided. The supplier has your money. You have an invoice HMRC will not accept.
Checking is proportionate to risk. Nobody needs to verify a supermarket receipt. It is worth doing for:
- new suppliers, before the first payment
- subcontractors, particularly in construction
- any single purchase with a material VAT amount
- suppliers whose invoices look inconsistent, or whose bank details change
- any supplier who has recently changed legal entity or been taken over
Frequently asked questions
Is there a free way to check a VAT number?
Yes. HMRC’s checker at gov.uk/check-uk-vat-number is free and needs no account. VIES, for EU numbers, is also free. You should not need to pay a third-party service for this.
Can I look up a company’s VAT number by name?
No. There is no searchable public register of UK VAT numbers, and the GOV.UK service requires the number as the input. Find it on an invoice, receipt or the supplier’s website, or ask them for it.
What is the difference between a VAT number and a company number?
They are unrelated. A company registration number is an eight-character reference issued by Companies House when a company is incorporated. A VAT number is nine digits issued by HMRC on VAT registration. A sole trader can have a VAT number and no company number at all.
Can I reclaim VAT if my supplier’s VAT number turns out to be invalid?
Not reliably. Input tax recovery depends on holding a valid VAT invoice showing the supplier’s registration number. If the number is invalid, HMRC can refuse the claim, and it is your reclaim at risk rather than the supplier’s.
How do I check a Northern Ireland VAT number?
Numbers with an XI prefix, used for goods moving between Northern Ireland and the EU, are validated through VIES rather than the GOV.UK service. GB-prefixed numbers go through GOV.UK.
Keeping your own VAT in order
Checking suppliers is the easy half. The harder half is making sure your own returns hold up — right rates, valid invoices behind every reclaim, filed on time under Making Tax Digital.
SmartFiling handles MTD VAT filing for a fixed fee, working directly from Xero, QuickBooks or FreeAgent. Every return is reviewed by an ICAEW Chartered Accountant before it reaches HMRC.
