Checking a VAT Number

Key facts

UK VAT numbers have 9 digits (e.g. GB 123 4567 89).
Check UK numbers using HMRC’s online VAT number checker.
Check EU numbers using the VIES system.
Verifying VAT numbers protects you from fraud and ensures valid input VAT claims.

UK VAT Number Format

A UK VAT registration number consists of 9 digits, usually written with a “GB” prefix for international trade (e.g. GB 123 4567 89). The number is assigned by HMRC when you register.^[1]

How to Check a UK VAT Number

Use HMRC’s free online tool:^[1]

Visit the Check a UK VAT number service on GOV.UK
Enter the 9-digit number
The tool confirms whether the number is valid and shows the registered business name and address

How to Check an EU VAT Number

For businesses in the EU, use the VIES (VAT Information Exchange System):^[2]

Select the member state
Enter the VAT number
The system confirms validity and shows the trader’s details

Post-Brexit: UK VAT numbers are no longer on the VIES system. Use HMRC’s separate tool for UK numbers. For Northern Ireland, the prefix “XI” is used for EU trade and can be checked on VIES.

Why Should You Check?

Fraud prevention — avoid fake invoices with invented VAT numbers
Valid input VAT claims — if the supplier’s VAT number is invalid, your input VAT claim could be rejected
Zero-rating exports — you may need to verify your customer’s VAT number to zero-rate a supply
Due diligence — HMRC expects businesses to take reasonable steps to verify their suppliers^[3]

Frequently Asked Questions

How do I check if a UK VAT number is valid?

Use HMRC’s free “Check a UK VAT number” service on GOV.UK. Enter the 9-digit number and it will confirm whether the registration is valid and show the registered business name and address.

How do I verify an EU VAT number?

Use the VIES (VAT Information Exchange System) on the European Commission website. Select the member state, enter the VAT number, and the system confirms validity and shows the trader’s details.

What format is a UK VAT number?

A UK VAT number has 9 digits, usually written with a GB prefix for international trade (e.g. GB 123 4567 89). Northern Ireland businesses use an XI prefix for EU trade.

Why is it important to check a supplier’s VAT number?

Checking VAT numbers protects you from fraud, ensures your input VAT claims are valid, and demonstrates the due diligence HMRC expects businesses to perform on their supply chain.

Sources

Check a UK VAT number — GOV.UK
VIES VAT number validation — European Commission
VAT guide (VAT Notice 700) — GOV.UK