Northern Ireland VAT number format
9 digits, or 12 digits for a branch/establishment
| VIES prefix | XI |
|---|---|
| Structure | 9 digits, or 12 digits for a branch/establishment |
| Pattern | ^(\d{9}|\d{12})$ |
| Company name via VIES | Yes |
| Address via VIES | Yes |
| Verified example | 197211009 — PROJECT PLUG LIMITED !! CLICK ENERGY |
Check digit
Same family as GB numbers (a mod-97 double-add-double exists); not enforced.
Vatline does not reject on this check. Only the structure is enforced, so a format-valid number can still turn out to be unregistered. Rejecting a genuine customer costs more than one extra lookup.
Watch out for
- XI is NOT an ISO country code: it exists only for the Windsor Framework (post-Brexit Northern Ireland). GB numbers go to HMRC, not VIES. GD/HA-prefixed numbers are UK-domestic and out of VIES scope.
Check a number
Known-good value: 197211009, which VIES returns as PROJECT PLUG LIMITED !! CLICK ENERGY.