Validate EU VAT Numbers via API (VIES) – cURL Guide

This guide shows how to check an EU VAT number programmatically using the /v1/validate-vat endpoint. You’ll get a copy‑paste cURL request, a typical JSON response, and best‑practice tips for reliability and compliance.

Endpoint

POST https://api.vatifytax.app/v1/validate-vat

Request (cURL)

Send your API key via the Authorization: Bearer <API_KEY> header and include the VAT number as JSON:

cURL

curl -s https://api.vatifytax.app/v1/validate-vat \
  -H "Authorization: Bearer " \
  -H "Content-Type": "application/json" \
  -d '{"vat_number":"DE811907980"}'

Typical Response

{
  "valid": true,
  "country_code": "DE",
  "vat_number": "811907980",
  "checked_at": "2025-09-12T10:21:00Z",
  "source": "VIES"
}

Best Practices for EU VAT Validation

Server‑side only: Keep API keys off the client. Call the API from your backend.
Retry/backoff: Official sources (e.g., VIES) can be temporarily unavailable. Implement exponential backoff.
Cache results: Cache positive validations for a short period to reduce latency and external calls.
Log checked_at: Store the timestamp for audits and reconciliation.
Handle edge cases: Whitespace, country prefix normalization, and temporary service errors.
Respect rate limits: Queue bursts and monitor HTTP status codes for graceful degradation.

Next steps

Ready to integrate? Start with the Free tier and read more about the features. If you need EU VAT rates or tax calculation, see the API examples on the landing page.