EU VAT Validation API Documentation

1. Quick VAT Validate — GET /validate

Instantly check if a VAT number is valid without creating an audit. Powered by VIESAC multi-source intelligence combining VIES, supported national registries, VIESAC SmartRouter™, VIESAC SmartCache™, and VIESAC AI Engine.

For quick lookups only — no audit record is stored. For a full, legally reliable verification with a timestamped certificate, use POST /audits.

curl -X GET "https://viesac.eu/api/v1/validate?vat=DE123456789" \
  -H "Authorization: Bearer YOUR_API_KEY"

$url = 'https://viesac.eu/api/v1/validate?' . http_build_query(['vat' => 'DE123456789']);
$ch = curl_init($url);
curl_setopt_array($ch, [
    CURLOPT_HTTPHEADER => ['Authorization: Bearer ' . $apiKey],
    CURLOPT_RETURNTRANSFER => true,
]);
$data = json_decode(curl_exec($ch), true);

// $data['status'] → 'valid' / 'invalid'

import requests

response = requests.get(
    "https://viesac.eu/api/v1/validate",
    headers={"Authorization": f"Bearer {api_key}"},
    params={"vat": "DE123456789"},
)
data = response.json()

# data["status"] → "valid" / "invalid"

const res = await fetch(
  `https://viesac.eu/api/v1/validate?${new URLSearchParams({ vat: 'DE123456789' })}`,
  { headers: { Authorization: `Bearer ${apiKey}` } }
);
const data = await res.json();

// data.status → "valid" / "invalid"

Response (200) — VAT is valid:

{
  "vat": "DE123456789",
  "country_code": "DE",
  "vat_number": "123456789",
  "status": "valid",
  "checked_at": "2026-03-16T12:00:00+00:00"
}

Response (200) — VAT is not valid:

{
  "vat": "DE000000000",
  "country_code": "DE",
  "vat_number": "000000000",
  "status": "invalid",
  "checked_at": "2026-03-16T12:00:00+00:00"
}

Response (200) — Audit required (VIES unavailable and no fallback result):

{
  "vat": "DE123456789",
  "country_code": "DE",
  "vat_number": "123456789",
  "status": "audit_required",
  "checked_at": "2026-03-16T12:00:00+00:00",
  "code": "audit_required",
  "next_step": "create_audit",
  "create_audit_url": "https://viesac.eu/app/vat-validation",
  "docs_url": "https://viesac.eu/api-docs"
}

Rate limit response (429):

{
  "error": "VAT validation limit exceeded. Your current plan allows 10 live VAT validations per hour.",
  "code": "rate_limit_exceeded",
  "limit": 10,
  "window": "1 hour",
  "retry_after": 1800,
  "upgrade_url": "https://viesac.eu/app/payment"
}

2. Get account — GET /account

Get plan and audit statistics.

curl -X GET "https://viesac.eu/api/v1/account" \
  -H "Authorization: Bearer YOUR_API_KEY"

$ch = curl_init('https://viesac.eu/api/v1/account');
curl_setopt_array($ch, [
    CURLOPT_HTTPHEADER => ['Authorization: Bearer '.$apiKey],
    CURLOPT_RETURNTRANSFER => true,
]);
$data = json_decode(curl_exec($ch), true);

response = requests.get("https://viesac.eu/api/v1/account",
    headers={"Authorization": f"Bearer {api_key}"},
)
data = response.json()

const res = await fetch("https://viesac.eu/api/v1/account", {
  headers: { "Authorization": `Bearer ${apiKey}` },
});
const data = await res.json();

Response (200):

{
  "plan": "FREE",
  "plan_label": "Free",
  "monthly_limit": 15,
  "requests_total": 120,
  "requests_this_month": 12,
  "requests_remaining": 3,
  "validation_hourly_limit": 10,
  "validation_requests_this_hour": 4,
  "validation_remaining_this_hour": 6,
  "upgrade_url": "https://viesac.eu/app/payment"
}

4. List audits — GET /audits

List audits with filters. Query params: limit, date_from, date_to, country_code, vat_number, order_number, invoice_number.

curl -X GET "https://viesac.eu/api/v1/audits?limit=50&country_code=DE&date_from=2026-02-01" \
  -H "Authorization: Bearer YOUR_API_KEY"

$url = 'https://viesac.eu/api/v1/audits?'.http_build_query(['limit'=>50,'country_code'=>'DE']);
$ch = curl_init($url);
curl_setopt_array($ch, [CURLOPT_HTTPHEADER=>['Authorization: Bearer '.$apiKey], CURLOPT_RETURNTRANSFER=>true]);
$data = json_decode(curl_exec($ch), true);

response = requests.get("https://viesac.eu/api/v1/audits",
    headers={"Authorization": f"Bearer {api_key}"},
    params={"limit":50,"country_code":"DE"},
)
data = response.json()

const res = await fetch(`https://viesac.eu/api/v1/audits?${new URLSearchParams({limit:50,country_code:'DE'})}`,
  { headers: { "Authorization": `Bearer ${apiKey}` } }
);
const data = await res.json();

Response (200):

{
  "data": [
    {
      "reference_number": "VAC-20260216-ABC123",
      "country_code": "DE",
      "vat_number": "123456789",
      "status": "valid",
      "company_name": "Example GmbH",
      "requested_at": "2026-02-13T12:00:00.000000Z",
      ...
    }
  ],
  "count": 1
}

5. Get audit — GET /audits/{reference_number}

Get full details of a single audit by its reference number.

curl -X GET "https://viesac.eu/api/v1/audits/VAC-20260216-ABC123" \
  -H "Authorization: Bearer YOUR_API_KEY"

$ref = 'VAC-20260216-ABC123';
$ch = curl_init('https://viesac.eu/api/v1/audits/'.$ref);
curl_setopt_array($ch, [
    CURLOPT_HTTPHEADER => ['Authorization: Bearer '.$apiKey],
    CURLOPT_RETURNTRANSFER => true,
]);
$data = json_decode(curl_exec($ch), true);

ref = "VAC-20260216-ABC123"
response = requests.get(f"https://viesac.eu/api/v1/audits/{ref}",
    headers={"Authorization": f"Bearer {api_key}"},
)
data = response.json()

const ref = 'VAC-20260216-ABC123';
const res = await fetch(`https://viesac.eu/api/v1/audits/${ref}`, {
  headers: { "Authorization": `Bearer ${apiKey}` },
});
const data = await res.json();

Response (200):

{
  "reference_number": "VAC-20260216-ABC123",
  "country_code": "DE",
  "vat_number": "123456789",
  "status": "valid",
  "vies": 1,
  "company_name": "Example GmbH",
  "company_address": "Example Str. 1\n10115 Berlin",
  "consultation_number": "12345678901234",
  "certificate_url": "https://viesac.eu/cert/...?locale=en",
  "certificate_xml_url": "https://viesac.eu/cert/.../xml",
  "certificate_urls": {"pdf_en":"...","pdf_locale":"...","xml":"..."},
  "requested_at": "2026-02-13T12:00:00.000000Z",
  ...
}

404 if reference not found: {"error":"No audit found for this reference number."}

7. Check partner — GET /partners/check?q=

Search by VAT (e.g. DE123456789) or company name. Returns full list per company with last status, last check date, and monitoring info if set.

curl -X GET "https://viesac.eu/api/v1/partners/check?q=DE123456789" \
  -H "Authorization: Bearer YOUR_API_KEY"

$q = urlencode('DE123456789');
$ch = curl_init('https://viesac.eu/api/v1/partners/check?q='.$q);
curl_setopt_array($ch, [
    CURLOPT_HTTPHEADER => ['Authorization: Bearer '.$apiKey],
    CURLOPT_RETURNTRANSFER => true,
]);
$data = json_decode(curl_exec($ch), true);

response = requests.get("https://viesac.eu/api/v1/partners/check",
    headers={"Authorization": f"Bearer {api_key}"},
    params={"q": "DE123456789"},
)
data = response.json()

const res = await fetch(`https://viesac.eu/api/v1/partners/check?${new URLSearchParams({q: 'DE123456789'})}`, {
  headers: { "Authorization": `Bearer ${apiKey}` },
});
const data = await res.json();

Response (200):

{
  "data": [
    {
      "company_name": "Example GmbH",
      "vat": "DE123456789",
      "country_code": "DE",
      "vat_number": "123456789",
      "address": "Example Str. 1\n10115 Berlin",
      "last_status": "valid",
      "last_check_date": "2026-02-13T12:00:00.000000Z",
      "monitoring": { "frequency": "month", "next_check_at": "2026-03-13T12:00:00.000000Z" }
    }
  ],
  "count": 1
}

If no partners match: data is [], count is 0, and message is included.