VAT registration number (Northern Ireland Protocol)
Northern Ireland VAT number format
Northern Ireland VAT numbers (VRN) are written as XI + 9 digits (same number as GB, used for trade in goods with the EU), for example XI980780684.
- Country code
- XI
- Format
- XI + 9 digits (same number as GB, used for trade in goods with the EU)
- Example
- XI980780684
- Local name
- VAT registration number (Northern Ireland Protocol)
- Register
- VIES (EU)
Regular expression
^XI(\d{9}|\d{12}|GD\d{3}|HA\d{3})$Checks the format only. The register confirms the rest.
Check a Northern Ireland VAT number
Include the country prefix. EU numbers are checked against VIES in real time, UK numbers with a separate live check.
How Northern Ireland VAT numbers are built
XI followed by the same digits as the business's GB number (9 digits, 12 with a branch code, or GD/HA plus 3 digits).
Check digit
As for GB numbers, vatcheckapi checks the format only; VIES confirms the number.
Common mistakes
- XI numbers are checked in VIES; the same number with GB is checked through a commercial VAT data service.
- The XI prefix is for trade in goods with the EU; for services the business uses its GB number.
Is the number registered?
A valid format and check digit only mean the number could exist. Whether it is currently registered for VAT is known to HM Revenue & Customs (HMRC), and VIES asks that register for you. Where Northern Ireland shares them, VIES also returns the registered name and address.
Check a Northern Ireland number with the validator above, in the VAT number checker or on the UK VAT checker page, or up to 50 at once with the bulk VAT validator.
Check Northern Ireland VAT numbers by API
curl "https://api.vatcheckapi.com/v2/check?vat_number=XI980780684" -H "apikey: YOUR-API-KEY"The response says whether the format and checksum are valid and whether the number is registered, with name and address where Northern Ireland provides them.
Frequently asked questions
What does a Northern Ireland VAT number look like?
How do I check a Northern Ireland VAT number?
Do Northern Ireland VAT numbers have a check digit?
What is the most common mistake with Northern Ireland VAT numbers?
Other countries
VAT validation API
Validate VAT numbers in your app
vatcheckapi checks the format and checksum of EU and UK VAT numbers and confirms the registration live (VIES for EU numbers), with company name and address where the country provides them.
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GET https://api.vatcheckapi.com/v2/check?vat_number=LU26375245
{
"country_code": "LU",
"vat_number": "26375245",
"format_valid": true,
"checksum_valid": true,
"registration_info": {
"is_registered": true,
"name": "AMAZON EUROPE CORE S.A R.L.",
"address": "38, AVENUE JOHN F. KENNEDY\nL-1855 LUXEMBOURG",
"address_parts": null,
"checked_at": "2026-10-16T09:12:44.000000Z"
},
"registration_info_history": []
}