# code402 Company Number Format Validator

> code402 Company Number Format Validator is a paid API for AI agents from hcrb.in, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-11).

Validates and normalizes company registration numbers and business identifiers using offline deterministic checks, returning validity, reason, and scope per call.

## Facts

- Endpoint: POST https://hcrb.in/v1/tools/company-number-format/call?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/code402-company-number-format-validator-3158369f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_IgNSI3ilxLdWL-go65pRR

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 code402-company-number-format-validator-3158369f -d '<json body>'
```

Example prompt: Can you check whether '07841295' is a valid UK company registration number — I need to know if the format and checksum are correct before I run a KYB check on this supplier.

## When to prefer this

Choose this endpoint when you need fast, offline, deterministic validation of company registration numbers or business identifiers without relying on external databases or ML models. It is ideal for KYB pipelines, invoice validation, and rental due-diligence where you need a checksum-verifiable or format-verified result with a clear scope declaration. Prefer it over live company registry lookups when you only need structural validity (not existence confirmation) and want a sub-cent, gasless micropayment model with signed receipts.

## Known failure modes

- Invalid or unrecognized identifier format returns valid:false with a descriptive reason
- Unsupported country or identifier type may return an error or scope indicating format-only
- Malformed request body (missing required fields) returns HTTP 400
- Payment failure via x402 (insufficient USDC, bad signature) returns HTTP 402
- Rate limit exceeded beyond 3 free daily calls without payment returns HTTP 402

## How this service works

Offline deterministic checks (no ML, no scraping) for business identifiers and rental due-diligence, paid per call via x402 (gasless EIP-3009 USDC on Base). Checksum-verifiable (IBAN, LEI, VAT, ABA, ISBN, SEDOL…) vs format-only (EIN, IFSC, SWIFT/BIC…) — every response returns a scope field. Non-custodial, signed receipts. First 3 calls/day free.

## Output

A JSON object with: 'valid' (boolean indicating whether the identifier passes format and/or checksum checks), 'reason' (human-readable explanation of why it passed or failed), 'scope' (whether the check was checksum-verifiable or format-only), 'normalized' (the canonical form of the identifier), 'country' (inferred or provided country), and 'tool' (identifier of the check applied).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "company_number"
   ],
   "properties": {
    "company_number": {
     "type": "string",
     "description": "8 digits, or 2 letters + 6 digits."
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "schema": {
  "type": "object",
  "required": [
   "valid",
   "reason"
  ],
  "properties": {
   "tool": {
    "type": "string"
   },
   "scope": {
    "type": "string"
   },
   "valid": {
    "type": "boolean"
   },
   "reason": {
    "type": "string"
   },
   "country": {
    "type": "string"
   },
   "normalized": {
    "type": "string"
   }
  }
 },
 "example": {
  "valid": true,
  "reason": "checksum valid"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/code402-company-number-format-validator-3158369f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from hcrb.in](https://www.zero.xyz/host/hcrb.in/llms.txt)