VAT VIES UK: which checker for GB or XI?
For a VAT VIES UK check, use HMRC for a GB VAT number and VIES for an XI Northern Ireland VAT number. Choose the checker by prefix, before entering the number.
Start with the prefix on the VAT document
GB: open the official HMRC checker. Have the VAT number ready; a business name alone is not enough. HMRC reports whether the registration is valid and the registered name and address.
XI: use the XI option in the linked VIES checker. HMRC explains that XI is used for qualifying Northern Ireland trade in goods with the EU; a UK address alone does not tell you which prefix to check.
Use the number supplied on the VAT document. Do not replace GB with XI just to make a VIES request: HMRC confirms when a business should start using XI.
GB: open the official HMRC checkerXI: open the VIES checkerHMRC: when to use an XI VAT number
Outside VIES does not mean invalid at HMRC
A checker that answers only from VIES has nothing to say about a GB number. That is a gap in coverage, not a verdict on the registration.
Recording a GB customer as invalid because an EU tool returned nothing is the expensive version of this mistake: the registration may be perfectly live at HMRC.
GB and XI are two different registers
XI numbers relate to Northern Ireland and remain answerable through VIES, which is why this checker accepts XI and not GB.
If a customer gives a number beginning with XI, select XI here. If it begins with GB, the answer lives with HMRC.
Both may appear on paperwork from the same company, so read the prefix rather than assuming from the address.
How to check a UK VAT number
Use the official HMRC Check a UK VAT number service for a GB registration. It confirms whether the number is valid and shows the registered business name and address.
Have the VAT number before you start: HMRC cannot search by business name. A UK VAT-registered business can also use its own VAT number to prove when it checked another number.
For an XI registration, use the XI option in the VAT checker on this page so the request goes to VIES instead of HMRC.
Can VIES check a UK VAT number?
It can check an XI VAT number for Northern Ireland. A GB VAT number is outside VIES, so use the official HMRC service instead.
Can I search a UK VAT number by company name? No. HMRC requires the VAT number itself; find it on the business invoice, receipt or website before starting the check.
What to do with a mixed customer list
Split the list by prefix before validating: GB to HMRC, XI and the 27 member states to VIES.
Keep the two sources labelled in your records. A single column that says only valid or invalid loses which register answered, and that is the detail an audit asks about.
Validating VAT numbers at volume?
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Related VIES guides
- VIES VAT checker: check an EU VAT numberCheck an EU VAT number against VIES, see a valid, invalid or unavailable result, and download a dated record. Review company details when the member state provides them.
- 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 explainedMS_UNAVAILABLE, MS_MAX_CONCURRENT_REQ, TIMEOUT, INVALID_INPUT and SERVICE_UNAVAILABLE — what each VIES error actually means, whether to retry, and which member states are down right now.
- VIES service unavailableWhat to do when VIES or a national VAT registry is unavailable.
- Is VIES down?Live VIES status, country by country. See which EU member-state VAT registries are answering right now, read from the European Commission's own availability table every 15 minutes.