EU VAT Validation API Built for Checkout Resilience
Validate EU VAT numbers through VIES, handle upstream outages with cached fallback, and store audit-ready receipts for checkout, billing, and compliance workflows.
REST API · Sandbox mode · Webhooks · Batch validation · Audit receipts · Source status
Quick start
Validate a VAT number with one API call.
Request
curl -X POST https://vatsignal.com/v1/vat/validate \
-H "Authorization: Bearer vs_test_your_key" \
-H "Content-Type: application/json" \
-d '{"vat_number": "DE123456789"}'Response
{
"request_id": "val_8f42c9",
"vat_number": "DE123456789",
"country_code": "DE",
"valid": true,
"source": "VIES",
"source_status": "live",
"fallback_used": false,
"action": "accept",
"checked_at": "2026-06-11T19:01:17Z",
"receipt_url": "/v1/validations/val_8f42c9/receipt.pdf"
}Why use VatSignal instead of calling VIES directly?
VIES is the source of truth, but production checkout and billing systems need retries, fallback decisions, observability, and audit evidence.
Live VIES validation
Validate VAT numbers against official EU VAT sources and get a structured API response for checkout and billing systems.
Checkout-safe fallback
When VIES or a member-state service is unavailable, return transparent source status and configurable fallback decisions instead of silently breaking checkout.
Audit receipts
Store validation evidence with request ID, timestamp, source status, result, and downloadable receipt.
Batch validation
Upload or submit large VAT lists and process them asynchronously without building your own queue system.
Webhooks
Receive validation results, batch completion events, and status notifications in your own system.
Source transparency
Expose upstream status, fallback usage, and circuit-breaker behavior in every relevant response.
Checkout resilience flow
Your checkout should not fail blindly because an upstream country VAT service is temporarily unavailable. VatSignal helps you separate “VAT is invalid” from “VAT source is unavailable.”
Validate live through VIES
Query official EU VAT sources and receive a structured response with source status.
Detect upstream failure
Timeouts and outages are surfaced as source_status: unavailable, not silent errors.
Return configured action
Accept, reject, or review — your system decides based on clear source status.
Built for real B2B VAT workflows
B2B SaaS checkout
Validate EU VAT IDs during signup, subscription checkout, or plan upgrades.
Invoicing and billing
Check VAT numbers before generating B2B invoices and store proof for future audit.
Shopify and ecommerce apps
Add resilient VAT validation to merchant checkout, customer approval, or tax-exemption workflows.
Finance operations
Batch-check customer lists, detect stale VAT records, and keep validation evidence organized.
Start validating VAT numbers in minutes
Create a sandbox key, test the API, and move to live validation when ready.