How to Store VIES VAT Validation Evidence
The official EU guidance recommends keeping track of VIES validations in case of a tax control. The useful artifact is not a screenshot alone; it is a reproducible, time-stamped record tied to the relevant transaction or customer decision.
Why keep a verification record?
VIES returns current information assembled from national VAT systems. The EU’s business guidance recommends keeping track of a validation in case of tax control. That recommendation matters because a later check may not recreate exactly what your system saw when a transaction was processed.
Your record should explain what number was checked, which service answered, when it answered and what the service actually returned. It should not be labelled as permanent proof that the business remained registered after that moment.
Minimum evidence fields
Keep the evidence close to the business event rather than in an unsearchable application log. Mask or restrict personal and address data according to your actual retention need.
- Normalized country code and VAT number.
- Valid, invalid or unavailable outcome.
- UTC check time and the VIES request identifier when returned.
- Name and address exactly as returned, including empty or unavailable fields.
- Provider name, response version or raw-response hash, and your internal request ID.
- Customer, invoice, order or account event that caused the check.
Do not flatten operational errors into invalid
The EU notes that VIES can be unavailable while national databases are backed up or maintained. Store that condition as unavailable and schedule a retry. An invalid result is a business response from the connected data; an unavailable result means the validation did not complete.
This distinction also affects charging. LookTwice returns 503 and charges zero when VIES is unavailable, leaving the caller free to retry without paying for an answer it did not receive.
Use evidence as an input, not tax advice
A valid VIES result can be important in cross-border VAT workflows, but the applicable tax treatment also depends on the transaction, parties, location and exceptions. The verification record documents one input to your process; it does not replace advice from a qualified tax professional.
If the customer says a number should be valid but VIES does not confirm it, official guidance directs them toward their national tax authority and notes that additional cross-border registration may be required.
Frequently asked questions
Is a screenshot enough evidence?
A screenshot may help, but a structured record is easier to associate with a transaction and should also retain the normalized input, UTC check time, outcome and request identifier when available.
Should I store the company name and address?
Only when your workflow needs them, and exactly as returned. Some member states do not return these fields, so missing data must remain missing rather than being filled from another source.
How long should VIES evidence be retained?
Retention depends on the jurisdictions and records relevant to your business. Define it with your tax and privacy advisers rather than assuming one EU-wide duration from the API result.