Guides · Updated 10 October 2026

What proof of a VAT number check should you keep?

What the EU rules expect before you zero-rate or reverse-charge, what a good record of a check contains, and why a screenshot isn’t enough.

Why the record matters

When you sell to an EU business without charging VAT, by zero-rating goods sent to another EU country or applying the reverse charge to services, you are relying on your customer being a VAT-registered business. If a tax inspector later disagrees, the VAT you didn't charge can become yours to pay, with interest and possibly penalties. A good record of the check is what shows you did what the rules ask.

What the EU rules say

For goods sent to another EU country, the customer's valid VAT number has been a condition for zero-rating since 2020 (Article 138 of the VAT Directive), alongside proof that the goods left the country and listing the sale in your EC Sales List.
For services, you may treat the customer as a business if they gave you their VAT number and you confirmed it is valid, together with their name and address, through VIES (Article 18 of Implementing Regulation 282/2011).

Both come down to the same thing: check the number in VIES before you invoice, compare the name and address, and be able to show that you did.

What a good record contains

The full VAT number checked, with its country prefix.
The date and time of the check.
Where it was checked: VIES, and which country's database answered.
The result: valid or not valid, not "could not check".
The registered name and address returned, where the country publishes them.
A consultation number, if you have one. When you include your own VAT number in the check, VIES can return a unique reference that the tax authority can trace back to that exact check. Some countries don't issue them.

Why a screenshot isn't enough

A screenshot of a VIES result is easy to take and easy to lose. It often cuts off the date or the consultation number, it isn't linked to the invoice it supports, and nobody can tell whether it was edited. Because VIES only answers about today, you can't go back later and prove that a number was valid on the day you invoiced. If the record is missing, the evidence is gone.

How long to keep it

Keep the record as long as the invoice it supports. VAT records must be kept for several years, and how many depends on the country, typically between five and ten. Six years in the UK, for example.

How Validitool records checks

Signed in, every VAT check is saved in your check history, with a PDF certificate showing who was checked, when, against which registry and with what result. The same goes for EORI and company register checks.
The Free plan includes 1 certificate download a month; paid plans have no limit.
Through the API, add your own VAT number to a check to get a consultation number back where the country issues one.

Check a VAT number

Free, no sign-up needed for a few checks a day.

This guide is general information, not tax or legal advice. Rules and their application differ by country and by transaction; check with an adviser for your situation.