Austria VAT Validation API
Validate Austria UID numbers via REST API. Backed by EU VIES (real-time) — returns registration status, company name, and address in a single call.
Quick start
CURL
curl -H "Authorization: Bearer YOUR_API_KEY" \ http://localhost:3000/api/v1/validate/AT/ATU12345678
Single validation
Validate one Austria VAT number. Returns full company details for valid numbers.
const res = await fetch(
'http://localhost:3000/api/v1/validate/AT/ATU12345678',
{ headers: { 'Authorization': 'Bearer YOUR_API_KEY' } }
);
const data = await res.json();
/*
{
"valid": true,
"status": "active",
"company_name": "Example GmbH",
"address": "Musterstraße 1, Austria",
"country_code": "AT",
"vat_number": "ATU12345678",
"cached": false,
"request_id": "req_01abc..."
}
*/Response format
{
"valid": true,
"status": "active",
"company_name": "Example Austria Ltd",
"address": "Musterstraße 1, Austria",
"country_code": "AT",
"vat_number": "ATU12345678",
"cached": false,
"request_id": "req_01abc..."
}| Field | Type | Description |
|---|---|---|
| valid | boolean | true if the number is registered and active |
| status | string | "active", "inactive", "not_found", or "invalid_format" |
| company_name | string | null | Registered company name (where available from authority) |
| address | string | null | Registered address (where available from authority) |
| country_code | string | ISO 2-letter code — always "AT" for this endpoint |
| vat_number | string | The VAT number as sent in the request |
| cached | boolean | true if result served from cache (valid: 24h, invalid: 1h) |
| request_id | string | Unique request ID for support and audit logs |
Batch validation
Validate up to 25 numbers in a single POST request. Numbers are processed in parallel — ideal for onboarding flows and nightly reconciliation.
curl -s -X POST http://localhost:3000/api/v1/validate \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"numbers": [
{ "country": "AT", "vat": "ATU12345678" },
{ "country": "AT", "vat": "ATU12345679" }
]
}'[
{
"vat": "ATU12345678",
"valid": true,
"status": "active",
"company_name": "Example Ltd",
"country_code": "AT",
"cached": false
},
{
"vat": "ATU12345679",
"valid": false,
"status": "not_found",
"country_code": "AT",
"cached": false
}
]Error codes
| HTTP status | Meaning | Action |
|---|---|---|
| 400 | Bad request — malformed VAT format | Check the VAT format against the pattern below |
| 401 | Missing or invalid API key | Pass a valid Bearer token in the Authorization header |
| 404 | Country not supported | Check /vat-api for the full list of supported countries |
| 422 | Validation failed — invalid format | The number does not match the expected format |
| 429 | Rate limit exceeded | Back off and retry after the Retry-After header value |
| 503 | Upstream authority unavailable | VIES/authority is temporarily down — retry with exponential backoff |
Austria VAT format reference
| Property | Value |
|---|---|
| Country code (ISO) | AT |
| Local name | UID (Umsatzsteuer-Identifikationsnummer) |
| Format | ATU + 8 digits |
| Regex | ^ATU[0-9]{8}$ |
| Example | ATU12345678 |
| Standard rate | 20% |
| Validation source | EU VIES (real-time) |
| VIES supported | Yes |
Austrian VAT numbers always start with ATU (not just AT). The U stands for Unternehmer (entrepreneur). Austria has one of the most active VIES registrations in Central Europe.
Frequently asked questions
What does the TaxID API return for a Austria VAT validation?
For a valid Austria VAT number the API returns: `valid: true`, `status: "active"`, plus `company_name` and `address` where available from EU VIES (real-time). For invalid numbers it returns `valid: false` with a reason code. All fields are documented in the API reference.
How fast is the Austria VAT validation API?
Cached results (valid numbers are cached 24h, invalid 1h) respond in under 10ms. Uncached requests that require a live lookup via EU VIES (real-time) typically complete in 100–400ms. The `cached` field in the response tells you whether the result came from cache.
What is the Austria VAT number format?
Austria VAT numbers (UID (Umsatzsteuer-Identifikationsnummer)) follow the pattern: ATU + 8 digits. A valid example is `ATU12345678`. The TaxID API validates the format locally before making any live request, so malformed numbers fail instantly without consuming your quota.
Can I validate multiple Austria VAT numbers in one request?
Yes. The batch endpoint (POST /api/v1/validate) accepts up to 25 VAT numbers in a single request, processed in parallel. This is ideal for bulk onboarding flows, nightly reconciliation jobs, or importing customer lists. Each item in the response array maps 1-to-1 with your input array.
Start validating Austria VAT numbers
Free plan — 100 validations/month. No credit card required.
Integrate with your stack:
More Austria resources:
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