VAT & Tax ID Validation API for Developers

The TaxID API validates VAT numbers, ABNs, and other tax IDs across 31+ countries via a single REST endpoint. This page is the quick-reference guide for developers: what the API accepts, what it returns, and how to handle every possible response. For step-by-step language-specific tutorials, see the Node.js, Python, PHP, and React guides linked at the bottom.

Authentication

All requests require an API key passed in the `Authorization` header. Get your key from the dashboard after signing up. There are two key types: live keys (`vat_live_...`) for production requests and test keys (`vat_test_...`) for development — test keys return predictable responses without consuming quota.

bash

# Always pass the key in the Authorization header
curl -H "Authorization: Bearer vat_live_xxxxxxxxxxxxxxxx" \
  https://taxid.dev/api/v1/validate/DE/DE123456789

# Never include the key in the URL — it would appear in server logs

Validate Endpoint

bash

GET https://taxid.dev/api/v1/validate/{country}/{vat_number}

# {country}     — two-letter country prefix (e.g. DE, GB, AU)
# {vat_number}  — the full VAT number including the country prefix

# Example:
GET https://taxid.dev/api/v1/validate/DE/DE123456789

Response Schema

Field	Type	Description
valid	boolean	Shorthand: true when status === 'active'
status	string	active \| inactive \| format_invalid \| service_unavailable
vat	string	Normalised VAT number as validated
country_code	string	Two-letter country prefix
company_name	string \| null	Registered company name (from national registry)
address	string \| null	Registered address (from national registry)
cached	boolean	true if served from TaxID response cache
request_id	string	Unique request ID — use as audit reference

Status Code Reference

Status	HTTP	Meaning	Correct action
active	200	VAT number is valid and currently registered	Apply zero-rate / reverse charge
inactive	200	VAT number exists but registration has lapsed	Charge standard VAT; reject exemption claim
format_invalid	200	Input does not match the country's VAT format	Show format hint to user; do not retry
service_unavailable	200	National registry temporarily offline	Charge standard VAT; re-validate later

Note

All four statuses return HTTP 200. The `status` field in the body drives your application logic, not the HTTP status code. A 4xx or 5xx response indicates an API-level error (invalid key, malformed request, rate limit exceeded).

Quick-Start Code

typescriptvalidate.ts

async function validateVat(vatNumber: string) {
  const country = vatNumber.slice(0, 2).toUpperCase();
  const vat = vatNumber.replace(/\s/g, '').toUpperCase();

  const res = await fetch(
    `https://taxid.dev/api/v1/validate/${country}/${vat}`,
    { headers: { Authorization: `Bearer ${process.env.TAXID_API_KEY}` } }
  );

  if (!res.ok) throw new Error(`API error: ${res.status}`);
  return res.json();
}

pythonvalidate.py

import os, requests

def validate_vat(vat_number: str) -> dict:
    country = vat_number[:2].upper()
    vat = vat_number.replace(' ', '').upper()
    resp = requests.get(
        f'https://taxid.dev/api/v1/validate/{country}/{vat}',
        headers={'Authorization': f'Bearer {os.environ["TAXID_API_KEY"]}'},
        timeout=5,
    )
    resp.raise_for_status()
    return resp.json()

phpvalidate.php

function validateVat(string $vatNumber): array {
    $country = strtoupper(substr($vatNumber, 0, 2));
    $vat = strtoupper(str_replace(' ', '', $vatNumber));

    $ch = curl_init("https://taxid.dev/api/v1/validate/{$country}/{$vat}");
    curl_setopt_array($ch, [
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_HTTPHEADER => ['Authorization: Bearer ' . getenv('TAXID_API_KEY')],
        CURLOPT_TIMEOUT => 5,
    ]);
    $response = json_decode(curl_exec($ch), true);
    curl_close($ch);
    return $response;
}

Country Coverage

The API covers 31+ countries. EU countries are validated via VIES; non-EU countries via their respective national registries.

→EU (27 countries): AT, BE, BG, CY, CZ, DE, DK, EE, EL/GR, ES, FI, FR, HR, HU, IE, IT, LT, LU, LV, MT, NL, PL, PT, RO, SE, SI, SK
→United Kingdom: GB (HMRC) and XI (Northern Ireland)
→Australia: AU (Australian Business Register)
→Norway: NO (Brønnøysund Register Centre)
→Switzerland: CH (Federal Tax Administration UID)

Rate Limits and Quotas

Plan	Monthly validations	Requests/second
Free	100	2
Starter	1,000	10
Growth	10,000	30
Scale	100,000+	Custom

When you exceed the rate limit, the API returns HTTP 429. Cache results for 24 hours to reduce API calls — the TaxID API already caches at the infrastructure level, but caching in your own application reduces latency and protects your quota.

Related guides

Full API documentation

Complete endpoint reference

Node.js quick start

First validation in 5 minutes

Python Django & Flask integration

Python framework integration guide