# Korean Business Registration Status Lookup (NTS via x402)

> Korean Business Registration Status Lookup (NTS via x402) is a paid API for AI agents from x402-research.kgy5612.workers.dev, paid per call via x402, $0.03/call, status unknown (last checked 2026-09-14).

Looks up Korean business registration status and tax type for one or more 10-digit business registration numbers via the National Tax Service (NTS) dataset, paid per-call with USDC on Base.

## Facts

- Endpoint: GET https://x402-research.kgy5612.workers.dev/kr-biz-status
- Price: $0.03/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/korean-business-registration-status-lookup-nts-via-x402-9616013a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_HdIdQk0QeH45Ew80wsyXz

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 korean-business-registration-status-lookup-nts-via-x402-9616013a
```

Example prompt: Can you check the Korean business registration status for company number 123-45-67890 — I need to know if they're still active and what tax type they're classified under before I wire them payment?

## When to prefer this

Use this endpoint when you need to verify the active registration status or tax classification of Korean businesses by their 사업자등록번호 (business registration number) and want a pay-per-call model with no subscription — especially for due diligence, KYB onboarding, or supplier verification workflows. It supports batch lookups of up to 5 numbers per call, making it efficient for small-batch checks. Prefer this over scraping NTS directly or managing API keys for data.go.kr.

## Known failure modes

- Invalid or malformed business registration number returns an error or empty result
- More than 5 numbers submitted at once may be rejected
- Payment failure via x402/USDC on Base blocks the request entirely
- NTS upstream data may be stale — as-of date may lag real-time changes
- Non-Korean (non-10-digit) registration numbers will not match any record
- Network timeout from the Cloudflare Worker or upstream data.go.kr API

## How this service works

Call to check Korea NTS businessman open/closed + tax type JSON (휴폐업/과세유형). Official data.go.kr. Not a people search. Not tax advice.

## Output

Returns a JSON object with an as-of date and an array of items, one per queried business number, each containing the business status in Korean (e.g. 계속사업자 = ongoing), a status code, tax type label and code, closure date if applicable, and unit consumer credit indicator. Also includes source metadata referencing the NTS dataset on data.go.kr and a caveat that results are not tax advice.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "b_no": {
   "oneOf": [
    {
     "type": "string"
    },
    {
     "type": "array",
     "items": {
      "type": "string"
     }
    }
   ],
   "description": "Required. One 10-digit Korean business registration number, or an array (max 5). Hyphens OK."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/korean-business-registration-status-lookup-nts-via-x402-9616013a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-research.kgy5612.workers.dev](https://www.zero.xyz/host/x402-research.kgy5612.workers.dev/llms.txt)