As of 13 August 2026, AI can only partly verify a UK VAT number.

What to actually do

1. Hand it to a person

   The route this page recommends

   A person who owns the outcome does this end to end, worth it when the failure is dear.

2. Use a tool built for this

   Second choice

3. Do it yourself

   The distant third

   A chat interface, chat-fluent skill, and roughly 15 minutes until you can act on the result.

   How to actually do it

   1. Open the official GOV.UK VAT number checker at https://www.gov.uk/check-uk-vat-number.
   2. Gather the supplier's VAT number from its invoice or other business document, plus the supplier name and address shown on that document.
   3. Paste the VAT number into the GOV.UK checker and submit it without changing its digits.
   4. Record the returned business name, address, registration status and the checker reference or confirmation details shown on the page.
   5. Paste the number, supplier details and recorded HMRC result into the prompt, then ask the chatbot to compare them.
   6. Compare the chatbot's summary against the GOV.UK result and your source document, and query the supplier before treating a mismatch or unavailable result as verified.

   Prompt

   Help me verify a UK VAT number using the official GOV.UK service, not a guessed format or an unofficial database. VAT number: [INSERT VAT NUMBER]. Supplier legal or trading name: [INSERT NAME]. Supplier address: [INSERT ADDRESS]. Tell me exactly what to enter into the GOV.UK checker, what result to record, and how to compare the returned details with the supplier information. Do not say the number is valid unless the official checker confirms it. If the checker result is unavailable, expired, or does not match the supplier details, say that it is unresolved and list the next step. Keep the answer factual and do not give VAT registration or tax advice.

   Open it prefilled in ChatGPT or Claude, or copy it into Gemini, which takes no prefill link.