VerSys
VAT / tax

VAT number validation

Validate VAT number format and build a repeatable evidence trail for invoicing and supplier onboarding.

What this check does

This check validates VAT number format and country structure before optional live registry evidence.

What is a VAT number?

A VAT number identifies a business registered for value-added tax. In the EU it is commonly used to support B2B invoicing, VIES checks and reverse-charge evidence.

What the result means

A format-valid result means the identifier matches expected national patterns.

What the result does not prove

It does not prove the business is currently registered unless live registry evidence is included.

When businesses should use it

  • Customer VAT capture
  • Supplier onboarding
  • Invoice review

Example workflow

  1. Check format.
  2. Add VIES evidence when relevant.
  3. Store the result with invoice or onboarding records.

Data sources

Country VAT-number patterns and, when requested, VIES or HMRC registry responses.

Limitations

Registry availability varies and tax treatment still depends on transaction facts.

Related checks

VIES VAT checkEvidence reportVAT tools

VAT evidence flow

VAT validation is useful when it records both the identifier checked and the source used. Format checks, VIES evidence and invoice notes answer different questions.

How to use this page in practice

Start with the public check when you need a quick answer, then move to signed-in evidence, batch processing or the API when the same control becomes part of a repeatable finance, tax or operations workflow.

FAQ

Is format validation enough for EU B2B invoices?

Usually no. Use VIES evidence when reverse charge or zero-rating decisions depend on active registration.