United Kingdom VAT number: format and validation

By Remco from Avatcado

Format

GB followed by 9 or 12 digits. The local term is VAT registration number (VRN, English).

Pattern: /^\d{9}(\d{3})?$/

  • The 12-digit form is the 9-digit VAT number plus a 3-digit branch or subsidiary identifier; conventionally written GB 123 4567 89
  • GB numbers are not in VIES since 1 January 2021; validate via HMRC's checker or the Check a UK VAT Number API
  • Rare GBGD and GBHA forms exist for government departments and health authorities and follow a different pattern

Example of a registered number: GB 823 8476 09

Check digit

United Kingdom VAT numbers carry a check digit (MOD 97 / MOD 9755): Weights 8 down to 2 over the first 7 digits with the last 2 digits as the check; registrations from about November 2009 use the parallel 9755 variant (add 55 before reducing mod 97). Widely documented, though not officially published by HMRC.

Check a United Kingdom VAT number

Validated live against the HM Revenue and Customs (HMRC) (official register).

Enter a VAT number to see the live API response

Validate via API

The same validation as an API call, with the example number above:

curl "https://api.avatcado.com/v1/validate?vat_number=GB823847609" \
  -H "Authorization: Bearer avat_live_your_api_key"
import Avatcado from "@avatcado/node";

const avatcado = new Avatcado("avat_live_your_api_key");
const { data, error } = await avatcado.vat.validate({
  vatNumber: "GB823847609",
});

if (data?.data.valid) {
  console.log(`Registered: ${data.data.company?.name}`);
}

Free tier includes 500 validations per month. Get an API key or read the API documentation.

Frequently asked questions

What is the UK VAT registration threshold?

GBP 90,000 of taxable turnover, in force since 1 April 2024 when it rose from GBP 85,000. Below it, registration is voluntary.

How do I check a UK VAT number since Brexit?

VIES stopped covering GB on 1 January 2021, so use HMRC's free online checker at gov.uk/check-uk-vat-number or the Check a UK VAT Number API, which returns the registered name and address.

What does a 12-digit GB number mean?

It is the standard 9-digit VAT number with a 3-digit suffix identifying a branch or subsidiary trading under the same registration; the first 9 digits alone are the registration.

Related guides

VAT rate in United Kingdom

The standard VAT rate in United Kingdom is 20%. Reduced rates: 5%, 0%. See all United Kingdom VAT rates.

Sources