Source: https://rivet.global/blog/uk-vat-number-check-for-customers
Published: 2026-07-15 · Updated: 2026-07-15 · By Alexia M.

# How to check a UK or EU VAT number before you invoice

How to check a UK VAT number with HMRC, an EU VAT number on VIES, what the formats look like, and why a valid number matters for reverse-charge invoices.

## Key takeaways

- UK VAT numbers have 9 digits after the GB prefix, and HMRC's online service confirms whether a number is valid and whose it is.
- Since Brexit, GB numbers are not checked on the EU's VIES; Northern Ireland businesses trading goods use XI numbers that VIES does check.
- A valid customer VAT number supports reverse-charge treatment on B2B services; keep the check result as evidence.
- EU VAT numbers start with the country code and are checked on VIES.

"UK VAT number check" and "uk vat number checker" are among the top completions for "uk vat". The check is quick and the record is worth keeping, because it is often your only evidence for not charging VAT.

## Where to check

| Number | Format | Where to check |
|---|---|---|
| UK | GB + 9 digits (some 12) | HMRC: Check a UK VAT number |
| Northern Ireland goods | XI + digits | VIES |
| EU | Country code + digits, e.g. DE, FR, NL | VIES |

HMRC's service shows the registered name and address. It can also give you a consultation number to keep as proof of when you checked.

## Why it matters on the invoice

A UK company selling consulting services to a business in the Netherlands applies the reverse charge: no UK VAT, and the Dutch customer accounts for VAT. The rule depends on the customer being a business. A valid VAT number, checked on VIES and saved, is the evidence HMRC expects.

A UK company selling to a UK business checks the GB number so the input VAT the customer claims is valid and the invoice is correct.

## A routine that takes a minute

1. Ask for the VAT number when the customer signs up.
2. Check it on HMRC's service or VIES.
3. Save the result with the date.
4. Put the number on every invoice.
5. Re-check yearly or if details change.

## Payments that match the invoice

Ask customers to pay with the invoice number as the reference. Payments that arrive with clear references are easier to match to the VAT record, and easier to show in an inspection.

## Paying into the United Kingdom: the local rail

| What | Detail |
|---|---|
| Local rail | Faster Payments |
| Run by | Pay.UK |
| Settlement | Seconds, 24/7; the scheme limit is £1,000,000, and each bank sets its own |

Bacs still carries most payroll and Direct Debits, on a three-day cycle.

Source: [Pay.UK: Faster Payment System](https://www.wearepay.uk/what-we-do/payment-systems/faster-payment-system/). Checked when this guide was last updated; the scheme's own page has the current figures.

## Where Rivet fits

Rivet gives UK companies GBP and EUR details on Growth and USD on every plan, with each receipt showing the payer and reference. Rivet is not a bank; regulated partner institutions hold the funds. See [selling to EU customers from a UK company](/blog/uk-company-selling-to-eu-customers-vat-and-euro-payments).

## Questions

### How do I check a UK VAT number?

Use HMRC's Check a UK VAT number service on GOV.UK. It confirms validity and shows the registered name and address.

### Can I check a UK VAT number on VIES?

Not for GB numbers since 1 January 2021. XI numbers, used for Northern Ireland goods trade with the EU, can be checked on VIES.

### Why does a valid number matter?

For B2B services to an EU business, the reverse charge depends on the customer being a business. A valid VAT number and a saved check are your evidence.

### What if the number is invalid?

Ask the customer to confirm it. If they are not VAT registered, you may need to treat the sale as B2C, with different VAT rules.