EU VAT guide
XI VAT number check
VIES can support XI VAT numbers used for certain Northern Ireland trade flows.
Why XI appears
XI is used in VAT contexts connected to Northern Ireland rather than as a standard EU member-state country code.
If a customer gives an XI VAT number, select XI in the checker rather than GB.
If the check fails
Confirm the exact prefix and number with the customer and verify whether the VAT registration is active for the intended transaction.
If VIES is unavailable, retry later before making a final decision.
Validating VAT numbers at volume?
Join the batch/API list for CSV validation, retries, audit exports, and developer access.
Related VIES guides
- VIES VAT checkerCheck an EU VAT number in VIES and understand what the response means.
- EU VAT number validationValidate EU VAT IDs and learn when VAT checks matter for cross-border trade.
- VIES consultation numberLearn what a VIES consultation number is and when it can appear.
- VIES errors explainedUnderstand common VIES errors such as MS_UNAVAILABLE, TIMEOUT, and SERVICE_UNAVAILABLE.
- VIES service unavailableWhat to do when VIES or a national VAT registry is unavailable.
- Is VIES down?Check whether the VIES gateway appears reachable and learn what VIES downtime means.