# EU VAT Number Offline Validator

> EU VAT Number Offline Validator is a paid API for AI agents from vat-validate.hergertsynthora.com, paid per call via x402, $0.001/call, status down (last checked 2026-09-15).

Validates EU VAT numbers offline using per-country format rules and check-digit algorithms, returning a deterministic JSON verdict with normalized number and country.

## Facts

- Endpoint: POST https://vat-validate.hergertsynthora.com/service
- Price: $0.001/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/eu-vat-number-offline-validator-64bb83e6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_FezV5kuFh871RzUNklLH1

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability eu-vat-number-offline-validator-64bb83e6 -d '<json body>'
```

Example prompt: Can you validate this VAT number for me — DE811197733 — and tell me if it's a legitimate German VAT number and what the normalized format is?

## When to prefer this

Prefer this endpoint when you need fast, offline, deterministic EU VAT validation without depending on VIES or any external government API. Ideal for real-time invoice processing, onboarding flows, or batch data enrichment where uptime and latency matter. Supports DE, ES, FR, IT, NL, PT, BE, AT, PL, SE and more.

## Known failure modes

- Invalid VAT format returns verdict false with country and normalization where possible
- Unknown country prefix returns error or false verdict
- Malformed input string may return parsing error
- x402 payment failure returns upstream error (no charge on upstream failure)
- Missing vat field in request body returns validation error

## How this service works

EU VAT number validation for agents: per-country format rules and check-digit algorithms (DE, ES, FR, IT, NL, PT, BE, AT, PL, SE...) executed offline — deterministic, no VIES dependency, instant JSON verdict with country and normalized number. $0.001 USDC via x402 on Base. SYNTHORA.

## Output

A JSON object containing a boolean validity verdict, the detected country code, and the normalized VAT number string. Returned instantly with no VIES dependency.

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "niche": "vat-validate",
  "result": {
   "valid": true,
   "country": "DE",
   "normalized": "DE811907980",
   "checkdigit_ok": true
  },
  "provenance": {
   "url": "algorithmic:eu-vat-checkdigits",
   "source": "EU VAT Number Validator"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/eu-vat-number-offline-validator-64bb83e6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from vat-validate.hergertsynthora.com](https://www.zero.xyz/host/vat-validate.hergertsynthora.com/llms.txt)