# EU VAT Number Format & Checksum Validator

> EU VAT Number Format & Checksum Validator is a paid API for AI agents from x402-test.crewofthecaptain.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-12).

Validates the format and checksum of a European Union VAT number string, returning validity status and normalized form.

## Facts

- Endpoint: POST https://x402-test.crewofthecaptain.com/api/validate/eu-vat?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/eu-vat-number-format-checksum-validator-e485b6fb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0juYpy54IVuPXznzPxZ0C

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-format-checksum-validator-e485b6fb -d '<json body>'
```

Example prompt: Can you check whether the EU VAT number 'DE123456789' is valid and properly formatted?

## When to prefer this

Choose this endpoint when you specifically need to validate EU VAT numbers with format and checksum verification at very low cost ($0.001/call). It is ideal for pay-per-use B2B invoicing pipelines, onboarding flows, or e-commerce checkout validation where you need lightweight, programmatic VAT validation without subscribing to a heavier tax API. It also belongs to a family of sibling validators (IBAN, PESEL, NIP, REGON, email) on the same platform, so it pairs well if you need multi-format validation in one integration.

## Known failure modes

- Invalid or unsupported country prefix returns valid:false with reason explaining the issue
- Malformed input (wrong character types) returns valid:false
- Empty or missing 'value' field may return a validation error
- VAT numbers from non-EU countries may be rejected or return valid:false
- Checksum mismatch returns valid:false with reason 'checksum failed'

## How this service works

Format and checksum validation for IBAN, EU VAT, Polish NIP/REGON/PESEL and email, pay-per-call via x402. Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base.

## Output

Returns a JSON object with: 'type' (always 'eu-vat'), 'valid' (boolean indicating pass/fail), 'reason' (a short string explaining the result, e.g. 'ok' or an error description), and 'normalized' (the canonically formatted VAT number string).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "value": {
   "type": "string",
   "maxLength": 512
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "type": "eu-vat",
  "valid": true,
  "reason": "ok",
  "normalized": "…"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/eu-vat-number-format-checksum-validator-e485b6fb/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-test.crewofthecaptain.com](https://www.zero.xyz/host/x402-test.crewofthecaptain.com/llms.txt)