# VAT Number Format Validator (EU + GB/CH/NO)

> VAT Number Format Validator (EU + GB/CH/NO) is a paid API for AI agents from api.strale.io, paid per call via x402, $0.0216/call, status unknown (last checked 2026-10-12).

Validates a European VAT number's format against country-specific algorithmic rules for all 27 EU member states plus GB, CH, and NO — without checking VIES.

## Facts

- Endpoint: GET https://api.strale.io/x402/vat-format-validate?utm_source=zero.xyz
- Price: $0.0216/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-strale-io-17966b36
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_7i1Gk4NnL8Y7Rq-FIsJrj

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 api-strale-io-17966b36
```

Example prompt: Can you check whether this VAT number is correctly formatted: SE556703748501? I just need a format check, not a VIES lookup.

## When to prefer this

Use this endpoint when you need fast, offline format validation of a VAT number before submitting invoices or forms, or when you want to pre-screen VAT numbers without consuming VIES quota. Prefer this over vat-validate when you only need structural/algorithmic checks, not live VIES registry confirmation.

## Known failure modes

- Missing or malformed vat_number parameter — returns 400 bad request
- Unrecognized country prefix — returns error indicating unsupported country
- VAT number with no country prefix — validation cannot be performed
- Network timeout or service unavailable — returns 5xx error

## How this service works

Validate a European VAT number format against country-specific rules. Pure algorithmic — does NOT check VIES. Use vat-validate for full VIES verification. Supports all 27 EU countries + GB, CH, NO.

## Output

Returns whether the VAT number matches the expected format for its country prefix, along with the detected country code and any format-specific validation details. Does not perform live VIES registry verification.

## Example request

```json
{
 "vat_number": "SE556703748501"
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "vat_number"
     ],
     "properties": {
      "vat_number": {
       "type": "string",
       "description": "VAT number including country prefix (e.g. SE556703748501)"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-strale-io-17966b36/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.strale.io](https://www.zero.xyz/host/api.strale.io/llms.txt)