Validate EU VAT numbers.
Even when VIES is down.

curl -H "Authorization: Bearer $VAT_API_KEY" \
  "https://vatapi.be/api/v1/vat/BE0684579082"

use Illuminate\Support\Facades\Http;

$vatNumber = 'BE0684579082';

// Throws on 4xx/5xx. On 429, wait the seconds in the Retry-After header.
$result = Http::withToken(config('services.vat_api.key'))
    ->acceptJson()
    ->timeout(20)
    ->get('https://vatapi.be/api/v1/vat/'.rawurlencode($vatNumber))
    ->throw()
    ->json();

// true = valid, false = invalid, null = no definitive answer right now (retry later)
$valid = $result['valid'];

const vatNumber = 'BE0684579082';

const response = await fetch(`https://vatapi.be/api/v1/vat/${encodeURIComponent(vatNumber)}`, {
  headers: { Authorization: `Bearer ${process.env.VAT_API_KEY}`, Accept: 'application/json' },
  signal: AbortSignal.timeout(20_000),
});
// On 429, wait the seconds in the Retry-After header.
if (!response.ok) throw new Error(`VAT API error ${response.status}`);
const result = await response.json();

// true = valid, false = invalid, null = no definitive answer right now (retry later)
console.log(result.valid, result.name, result.source, result.checked_at);

import os
from urllib.parse import quote

import requests

vat_number = "BE0684579082"

response = requests.get(
    f"https://vatapi.be/api/v1/vat/{quote(vat_number, safe='')}",
    headers={"Authorization": f"Bearer {os.environ['VAT_API_KEY']}", "Accept": "application/json"},
    timeout=20,
)
response.raise_for_status()  # on 429, wait response.headers["Retry-After"] seconds
result = response.json()

# True = valid, False = invalid, None = no definitive answer right now (retry later)
print(result["valid"], result["name"], result["source"], result["checked_at"])