ICP Filing Lookup API

Last updated: 2026-10-19

GET /api/v2/icp/query?domain={domain}

Returns ICP filing records for a domain filed in mainland China. Base URL, response format and rate limits are shared across endpoints — see the API documentation.

Parameter	In	Description
`domain`	query	Domain or URL to look up. Whitespace, scheme, userinfo, path, query, port and a trailing dot are stripped. IP addresses are not supported. IDNs may be passed in Unicode or punycode.

The API extracts the registrable domain before querying: www.baidu.com becomes baidu.com, and a.b.example.com.cn becomes example.com.cn. The suffix is checked against the MIIT-approved list (171 suffixes). .com, .cn, .net, .top, .xyz, .中国, .公司 and similar suffixes are supported; .org, .io, .us and other unapproved suffixes return api.param.domain.suffix_unsupported.

Example:

curl "https://tcp.lc/api/v2/icp/query?domain=baidu.com"

Response data fields:

Field	Description
`domain`	Registrable domain that was queried. IDNs are returned in Unicode.
`suffix`	Top-level suffix used for validation, such as `.com` or `.中国`. For `example.com.cn` this is `.cn`.
`filed`	`true` when at least one filing record was found.
`records`	Filing records; empty when `filed` is `false`.
`source`	`primary` (preferred source) or `fallback` (secondary source).
`fetchedAt`	ISO 8601 time when the data was fetched from the source. Cache hits keep the original fetch time.
`cached`	`true` when this response was served from the server-side cache.

Each record contains:

Field	Description
`domain`	Domain covered by the record.
`mainLicence`	Entity filing number (主体备案号).
`serviceLicence`	Website filing number (网站备案号).
`unitName`	Registrant or entity name.
`natureName`	Entity type, such as `企业` or `个人`; usually in Chinese.
`contentType`	Pre-approval items, when present.
`limitAccess`	Access restriction flag, when present.
`siteName`	Website name when the source provides it; otherwise `null`.
`updatedAt`	Approval / last update time from the filing system.

Example:

{
  "code": 200,
  "msg": "ok",
  "data": {
    "domain": "baidu.com",
    "suffix": ".com",
    "filed": true,
    "records": [
      {
        "domain": "baidu.com",
        "mainLicence": "京ICP证030173号",
        "serviceLicence": "京ICP证030173号-1",
        "unitName": "北京百度网讯科技有限公司",
        "natureName": "企业",
        "contentType": "",
        "limitAccess": "",
        "siteName": null,
        "updatedAt": "2019-05-16 16:06:21"
      }
    ],
    "source": "primary",
    "fetchedAt": "2026-10-19T04:12:00.000Z",
    "cached": false
  }
}

A domain with no filing is not an error. The response is still code: 200, with filed: false and an empty records array:

{
  "code": 200,
  "msg": "ok",
  "data": {
    "domain": "example.com",
    "suffix": ".com",
    "filed": false,
    "records": [],
    "source": "primary",
    "fetchedAt": "2026-10-19T04:12:00.000Z",
    "cached": false
  }
}

Errors

Failures use code: -1000, with msg set to a stable identifier. data.args may carry details.

`msg`	Meaning
`api.param.domain.missing`	No `domain` parameter was provided.
`api.param.domain.invalid`	The input could not be parsed as a domain. `data.args.name` carries the input.
`api.param.domain.ip_unsupported`	IP addresses are not supported.
`api.param.domain.suffix_unsupported`	The suffix is not on the MIIT-approved list. `data.args.suffix` carries it, e.g. `.org`.
`api.rate.limitedDaily`	The daily quota is exhausted. A `Retry-After` header is included.
`api.upstream.icp.error`	Both filing sources are unavailable, a source timed out, or its response was invalid.
`api.server.internal`	Server or configuration error.

Example:

{
  "code": -1000,
  "msg": "api.param.domain.suffix_unsupported",
  "data": {
    "args": {
      "suffix": ".org"
    }
  }
}

Notes

filed: false means no record was found. The domain may be unfiled, registered outside mainland China, or its filing may have been cancelled.
Chinese IDN domains are supported. If the preferred source is unavailable, an IDN query may return api.upstream.icp.error instead of a possibly incorrect filed: false, because the fallback source cannot reliably resolve IDN names.
Filing data changes slowly but is not real-time. Use fetchedAt and the official MIIT filing system for verification.

Rate limits and caching

20 upstream lookups per day per client IP. Cache hits are free and do not consume the quota. The daily quota resets at 00:00 UTC+8; when exhausted, the endpoint returns api.rate.limitedDaily with a Retry-After header in seconds.

Filed results are cached for 7 days and unfiled results for 24 hours. The API response is sent with Cache-Control: no-store; caching happens on the server. Check cached to see whether the result came from the cache.