# UK Companies House Change Monitor (official API) (`plotbench/companies-house-change-monitor`) Actor

Watch UK companies for changes — name, status, registered office, SIC codes, officer count, new filings, accounts due dates — via the official Companies House API (free key). Schedule it and pipe change events to email/Slack/webhooks.

- **URL**: https://apify.com/plotbench/companies-house-change-monitor.md
- **Developed by:** [Plotbench Studio](https://apify.com/plotbench) (community)
- **Categories:** Automation, Lead generation
- **Stats:** 2 total users, 1 monthly users, 94.1% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

from $10.00 / 1,000 change detecteds

This Actor is paid per event and usage. You are charged both the fixed price for specific events and for Apify platform usage.

Learn more: https://docs.apify.com/platform/actors/running/actors-in-store#pay-per-event

## What's an Apify Actor?

Actors are web data automations that power AI and operations. They run on the Apify platform to scrape websites, process data, connect APIs, and automate workflows.
In Batch mode, an Actor accepts a well-defined JSON input, performs an action which can take anything from a few seconds to a few hours,
and optionally produces a well-defined JSON output, datasets with results, or files in key-value store.
In Standby mode, an Actor provides a web server which can be used as a website, API, or an MCP server.
Actors are written with capital "A".

## How to integrate an Actor?

If asked about integration, you help developers integrate Actors into their projects.
You adapt to their stack and deliver integrations that are safe, well-documented, and production-ready.
The best way to integrate Actors is as follows.

- **AI agents and MCP clients** — the [Apify MCP server](https://docs.apify.com/integrations/mcp.md) at `https://mcp.apify.com` (remote, streamable HTTP, OAuth on first use).
- **Agentic workflows and local Actor development** — [Agent Skills](https://apify.com/.well-known/agent-skills/index.json) with the [Apify CLI](https://docs.apify.com/cli/docs.md): `npm install -g apify-cli`, then `apify login`.
- **JavaScript/TypeScript projects** — the official [JS/TS client](https://docs.apify.com/api/client/js/docs.md): `npm install apify-client`.
- **Python projects** — the official [Python client](https://docs.apify.com/api/client/python/docs.md): `pip install apify-client`.
- **Any other language** — the [REST API](https://docs.apify.com/api/v2.md).

For usage examples, see the [API](#api) section below.

For more details, see Apify documentation as [Markdown index](https://docs.apify.com/llms.txt) and [Markdown full-text](https://docs.apify.com/llms-full.txt).

# README

## UK Companies House Change Monitor (official API)

Watch any list of UK companies and get a **change event** every time something moves: company name, status (active → liquidation…), registered office, SIC codes, active-officer count, accounts / confirmation-statement due dates, and **new filings**. Powered by the **official Companies House REST API** (free key). Schedule it daily or weekly and pipe change events to email, Slack or a webhook.

Built for people who monitor companies for a living:

- **Credit control & finance teams** — know the day a customer files for liquidation or changes its registered office, not the month after.
- **Suppliers & procurement** — counterparty watch across your vendor list.
- **Accountants & company secretaries** — accounts and confirmation-statement due dates across the whole client book, plus proof of filing the moment it lands.
- **B2B sales & PE/M\&A researchers** — name changes, new filings and officer movements as signals.

### How it works

Each run snapshots every company (profile + officers + latest filing = 3 API calls, rate-limit safe), diffs against the previous run's snapshot stored in a named key-value store in your account (`companies-house-monitor-state`, so it persists across scheduled runs), and pushes **one dataset row per detected change**:

```json
{
    "companyNumber": "07654321",
    "companyName": "SAMPLE GROUP HOLDINGS PLC",
    "event": "companyStatus-changed",
    "field": "companyStatus",
    "before": "active",
    "after": "liquidation",
    "detectedAt": "2026-07-05T01:24:31.201Z"
}
```

First run per company emits a `baseline-created` row; changes flow from the second run. Event types: `companyName-changed`, `companyStatus-changed`, `companyType-changed`, `sicCodes-changed`, `registeredOffice-changed`, `accountsNextDue-changed`, `confirmationStatementNextDue-changed`, `officersActiveCount-changed`, `new-filing`.

### Setup (2 minutes)

1. Get a **free** API key: [developer.company-information.service.gov.uk](https://developer.company-information.service.gov.uk) → register an application → REST API key.
2. Paste it into the `apiKey` input field (stored as an Apify secret).
3. Add your company numbers and create a Schedule (daily 07:00 works well).

No key yet? Run with `"mockMode": true` to see the change-detection engine work on bundled example fixtures.

### Input

```json
{
    "companyNumbers": ["01234567", "SC123456"],
    "apiKey": "YOUR_FREE_CH_KEY",
    "emitSnapshots": false
}
```

### Pricing (pay per event)

| Event | Price |
|---|---|
| Actor start | $0.02 per run |
| Company checked | $0.005 per company per run |
| Change detected | $0.01 per change |

Watching 100 companies daily costs about **$0.52/day** plus a penny per actual change — cheaper than one missed insolvency.

### Fair use & data sources

Uses the **official Companies House REST API** under your own free API key, within the published rate limit (600 requests / 5 minutes — the actor self-throttles to stay inside it). Companies House data is Crown copyright public data, free to use including commercially under the Companies House usage terms. No scraping.

### Limitations (told straight)

- Officer-level detail: v1 tracks the **active-officer count**, not per-officer appointments/resignations (that's the natural v2 — tell me if you want it).
- Change detection is per-run: schedule cadence = detection latency. Companies House also offers a streaming API; this actor deliberately uses the simpler REST polling model for reliability.
- PSC (persons with significant control) changes are not yet watched (v2 candidate).

# Actor input Schema

## `companyNumbers` (type: `array`):

Companies House company numbers to monitor (8 characters, e.g. 01234567 or SC123456).

## `apiKey` (type: `string`):

FREE REST API key from https://developer.company-information.service.gov.uk (register an application). Required for live monitoring.

## `mockMode` (type: `boolean`):

Run the change-detection engine on bundled example fixtures — no API key, no live calls. Untick and supply your API key for live monitoring.

## `emitSnapshots` (type: `boolean`):

Push the full per-company snapshot to the dataset on every run, in addition to change events.

## Actor input object example

```json
{
  "companyNumbers": [
    "00000006"
  ],
  "mockMode": true,
  "emitSnapshots": false
}
```

# API

You can run this Actor programmatically using our API. Below are code examples in JavaScript, Python, and CLI, as well as the OpenAPI specification and MCP server setup.

## JavaScript example

```javascript
import { ApifyClient } from 'apify-client';

// Initialize the ApifyClient with your Apify API token
// Replace the '<YOUR_API_TOKEN>' with your token
const client = new ApifyClient({
    token: '<YOUR_API_TOKEN>',
});

// Prepare Actor input
const input = {
    "companyNumbers": [
        "00000006"
    ],
    "mockMode": true
};

// Run the Actor and wait for it to finish
const run = await client.actor("plotbench/companies-house-change-monitor").call(input);

// Fetch and print Actor results from the run's dataset (if any)
console.log('Results from dataset');
console.log(`💾 Check your data here: https://console.apify.com/storage/datasets/${run.defaultDatasetId}`);
const { items } = await client.dataset(run.defaultDatasetId).listItems();
items.forEach((item) => {
    console.dir(item);
});

// 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/js/docs

```

## Python example

```python
from apify_client import ApifyClient

# Initialize the ApifyClient with your Apify API token
# Replace '<YOUR_API_TOKEN>' with your token.
client = ApifyClient("<YOUR_API_TOKEN>")

# Prepare the Actor input
run_input = {
    "companyNumbers": ["00000006"],
    "mockMode": True,
}

# Run the Actor and wait for it to finish
run = client.actor("plotbench/companies-house-change-monitor").call(run_input=run_input)

# Fetch and print Actor results from the run's dataset (if there are any)
print("💾 Check your data here: https://console.apify.com/storage/datasets/" + run["defaultDatasetId"])
for item in client.dataset(run["defaultDatasetId"]).iterate_items():
    print(item)

# 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start

```

## CLI example

```bash
echo '{
  "companyNumbers": [
    "00000006"
  ],
  "mockMode": true
}' |
apify call plotbench/companies-house-change-monitor --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "command": "npx",
            "args": [
                "mcp-remote",
                "https://mcp.apify.com/?tools=plotbench/companies-house-change-monitor",
                "--header",
                "Authorization: Bearer <YOUR_API_TOKEN>"
            ]
        }
    }
}

```

## OpenAPI specification

Download the OpenAPI definition: https://api.apify.com/v2/acts/2Glnm4vvGJetboKls/builds/JRTvsbzaL0O1ZqzHl/openapi.json