companieswise

Verified UK company lookup & number validation for AI agents — official Companies House data, not guesses.

Verified, trustworthy data tools for AI agents. "Qiniso" means "truth" in Zulu.

Ask an LLM "what's the registered name and status of company 00445790?" and it will answer confidently — and usually wrongly: invented names, the wrong status, a fabricated incorporation date. Company records live in the Companies House register, not a model's weights. companieswise looks the number up in the official Companies House snapshot and returns the real registered details — or an honest "not found" instead of a guess.

⚠️ Read this first — what the data is

UK-wide (England & Wales, Scotland, Northern Ireland).
A monthly snapshot of the live register. Company status is as of the dataset date, not real-time — a company dissolved last week may still read "Active" until the next snapshot, and dissolved companies are generally absent. For current status, check the live register.
Not advice. Not legal, financial, credit, or KYC/AML advice, and not a substitute for statutory due diligence.

Install

config.json

{ "mcpServers": { "companieswise": { "command": "npx", "args": ["-y", "companieswise"] } } }

Then load the real data once (the package ships with only a small sample):

Terminal

npx -p companieswise companieswise-update

This downloads the latest monthly Companies House snapshot (~tens of MB) to a local cache. Re-run it whenever you want to refresh; a GitHub Action rebuilds the snapshot monthly, so companieswise-update always fetches the current month. Until you run it, validate_company_number works fully and lookup_company/search_company clearly say they're on the sample.

Optional: live mode (BYO key)

By default companieswise serves the monthly snapshot (offline, no key). If you set a free Companies House API key, it switches to live queries against the official Companies House API instead — real-time register status, including dissolved companies, on your own key (no shared rate limit):

config.json

{
  "mcpServers": {
    "companieswise": {
      "command": "npx",
      "args": ["-y", "companieswise"],
      "env": { "COMPANIESWISE_CH_API_KEY": "your-companies-house-api-key" }
    }
  }
}

lookup_company and search_company use the live API when the key is set (results tagged "dataset": "live") and fall back to the snapshot when it isn't ("dataset": "snapshot"), so it's always clear which you're getting. validate_company_number is offline either way. The key is sent only to the official Companies House API. CH_API_KEY is accepted as an alias.

Use it as a library

Terminal

npm i companieswise

server.ts

import { lookupCompany, validateCompanyNumber, searchCompany } from "companieswise";

validateCompanyNumber("SC123456");   // { valid: true, prefix: "SC", meaning: "Company registered in Scotland" }
validateCompanyNumber("6").number;   // "00000006" — normalises/zero-pads
lookupCompany("00000006");           // official name, status, type, incorporation date, postcode, SIC — or found:false
searchCompany("greggs");             // companies whose registered name contains your words

A well-formed number that isn't in the snapshot returns found: false with a clear note — it never invents a company.

Tools — 3

Tool	What it answers
lookup_company	A company's official registered details by number (name, status, type, incorporation date, registered postcode, primary SIC)
validate_company_number	Is this a well-formed UK company number, and what does its prefix denote? (format only — there is no check digit)
search_company	Reverse lookup — find a company's number from its name

Data & monthly auto-refresh

The data is the Companies House Free Company Data Product (UK-wide, live register), published under the Open Government Licence v3.0. Because the real dataset is ~5.6M companies — far too large to bundle into an npm package — the design splits code from data:

Code ships on npm (tiny).
Data is built monthly by a GitHub Action (.github/workflows/refresh-data.yml) that downloads the official snapshot, compiles a compact artifact, and publishes it as a GitHub Release asset.
companieswise-update downloads that artifact into a local cache; every response reports its datasetVersion (the snapshot date).

No API key, no rate limit, no per-request cost — lookups run locally against the cached snapshot. See ARCHITECTURE.md for why, and the hosted/real-time path.

What it is not

Not real-time. Monthly snapshot of the live register; status is as of the dataset date. For live status use the Companies House API/website.
Not the full register. The free snapshot is live companies; dissolved companies are generally absent (absent ≠ "never existed").
Not advice, and not a statutory KYC/AML check.
Not a guesser — unknown numbers return an honest "not found".

Privacy

This tool runs locally on your machine and is built not to collect, store, or transmit your data — no analytics, no telemetry, no account. By default it uses bundled/cached data offline; only if you set a Companies House API key does it send your lookup and key directly to the official Companies House API (never to Qiniso). Full policy: https://qinisolabs.github.io/privacy.html.

Companieswise README