What is the Northern Ireland VAT?

Northern Ireland VAT numbers carry the XI country prefix introduced under the Northern Ireland Protocol and are issued by HM Revenue & Customs (HMRC).

What formats can a Northern Ireland VAT number take?

Northern Ireland VAT numbers appear in three forms:

• XI999 9999 99 — the standard format: the XI prefix followed by 9 digits.
• XI999 9999 99 999 — the standard format with an additional 3-digit block identifying branch traders.
• XIGD9996 or XIHA9997 — the XI prefix followed by a 5-character block, used for Government Departments (GD) and Health Authorities (HA).

How can I validate a Northern Ireland VAT online?

You can validate any Northern Ireland VAT using Lookuptax's free checker above. Enter the VAT to confirm it is valid and retrieve the registered entity details instantly.

Why should I validate a VAT before invoicing?

Checking a counterparty's VAT before you invoice helps you catch typos and stale identifiers early, keeps customer records accurate, and reduces the risk of rejected filings or disputed invoices later on.

Can I integrate VAT validation into my billing system?

Yes. Lookuptax provides a tax ID validation API that can be integrated with invoicing, ERP, or billing platforms to automate Northern Ireland VAT checks.