# VAT Number Validation API

> VAT Number Validation API is a paid API for AI agents from gateway.apiosk.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-15).

Validates a VAT (Value Added Tax) number, returning its validity, associated country, and checksum correctness

## Facts

- Endpoint: POST https://gateway.apiosk.com/financial-identifiers/validate/vat
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/vat-number-validation-api-596a8484
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__fXI_gJkXOV06gzKIgHWQ

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 vat-number-validation-api-596a8484 -d '<json body>'
```

Example prompt: Can you validate this VAT number for me — NL854285197B01 — and tell me if it's valid, which country it belongs to, and whether the checksum checks out?

## When to prefer this

Use this endpoint when you need to validate a VAT number for invoicing, B2B onboarding, or tax compliance purposes and want both structural (checksum) and country-level verification in a single call. Prefer this over manual regex checks when you need authoritative checksum validation across multiple EU country formats.

## Known failure modes

- Invalid or malformed VAT string returns valid:false with checksum_valid:false
- Unsupported country prefix may result in unknown country field or error
- Empty or missing vat field causes request validation error
- Network or gateway timeout returns HTTP 5xx

## How this service works

Validate an EU VAT number with per-country syntax and available offline checksum algorithms.

## Output

Returns a JSON object indicating whether the VAT number is valid (ok, valid flags), the two-letter ISO country code the VAT number belongs to (e.g. 'NL' for Netherlands), and whether the checksum is mathematically valid (checksum_valid).

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/vat-number-validation-api-596a8484/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from gateway.apiosk.com](https://www.zero.xyz/host/gateway.apiosk.com/llms.txt)