Before Brexit, the European Commission's VIES service answered for UK numbers too. No longer: a GB VAT number submitted to VIES is rejected, not because the supplier is dubious, but because GB numbers left the EU system. The split today is clean:
- GB numbers → HMRC's Check a UK VAT number service on gov.uk. It confirms whether the number is registered and returns the registered business name and address.
- EU member-state numbers → VIES, which validates against each member state's national database.
- XI-prefixed numbers (Northern Ireland trading in goods under the Windsor Framework) remain visible to VIES.
Why check at all, and why keep the receipt
If a supplier's number turns out to be invalid or belongs to someone else, your input tax position is exposed. Checking the register at the time of the transaction, and keeping evidence of when you checked and what it said, is the difference between "we verified this" and "we assumed". HMRC's own service supports this by letting you obtain proof of the check.
NoticeDesk routes each lookup to the right register automatically based on the country prefix (VIES for EU numbers, HMRC's Check-a-UK-VAT-number service for GB), compares the registered name against the invoice, and stores the verdict with the extraction. A lookup that can't be completed is recorded as unverified, so it stays visible and can be re-checked later.