UK Companies House Monitor — Filings, Directors, Charges & New Incorporations

A change feed on UK companies, straight from the official Companies House register. Give it a list of company numbers, schedule it, and every run emits only what moved since the last one: new filings, directors appointed and resigned, status changes, registered charges. Or run it in lead-gen mode and get every newly incorporated UK company matching your SIC codes.

Most Companies House actors on the store are one-shot scrapers: they hand you a snapshot and leave the diffing to you. This one keeps the baseline and does the diffing, so a scheduled run gives you events, not a re-download.

Built for:

• KYC, onboarding & compliance — get told the day a customer enters liquidation, changes control, or appoints a director you need to re-screen. Watch your whole book; a quiet run costs pennies.
• Credit & risk teams — a new registered charge means someone else has taken security over the assets. A satisfied charge means they let it go. Both land here the day they hit the register.
• Sales & GTM intelligence — lead-gen mode lists companies incorporated in the last N days filtered by SIC code. A brand-new company in your sector, with its registered office and postcode, before anyone has sold to it.
• Supplier & counterparty monitoring — strike-off notices (GAZ1), overdue accounts and status changes across every supplier you depend on.
• Journalists & researchers — watch a set of companies and get a clean, timestamped event log instead of refreshing the register by hand.

You bring your own API key (free, about 5 minutes)

Companies House publishes this data through a free official API, and this actor runs on your own key — so the quota and the 600-requests-per-5-minutes rate limit are yours alone, not shared with every other buyer.

1. Go to developer.company-information.service.gov.uk and sign in (creating an account is free).
2. Click Create an application — choose the Live environment.
3. In the application, click Create new key and choose key type REST (not "Streaming").
4. Leave the IP restriction empty — the actor runs on Apify's servers, so a restricted key will be rejected.
5. Paste the key into the actor's API key input. It is stored encrypted (isSecret), and never appears in your dataset or logs.

That is the whole setup. There is no charge from Companies House.

How the diffing works

• Run 1 seeds a baseline for each company and emits nothing. That is correct and deliberate: without it, adding Tesco to your watch list would dump 8,371 historical filings into your dataset.
• Every later run emits only the differences. A filing is identified by the register's own permanent transaction id, an officer by their appointment link, a charge by its charge link — so nothing is ever reported twice.
• A company added later seeds on its own first run, and one removed from the list is forgotten (re-adding it re-seeds rather than replaying history).
• maxItems is shared fairly across every watched company, so one busy plc cannot crowd out the other 699. Anything over the cap is not marked as seen and arrives on the next run — you are never billed twice, and never lose a change.

Example output

{
  "companyNumber": "00102498",
  "companyName": "BP P.L.C.",
  "eventType": "filing",
  "summary": "Secretary resignation filed",
  "filingType": "TM02",
  "effectiveDate": "2026-08-18",
  "officersAffected": [],
  "status": "active",
  "url": "https://find-and-update.company-information.service.gov.uk/company/00102498",
  "detectedAt": "2026-09-01T01:51:29Z",
  "details": {
    "transactionId": "MzUzOTMzMzcwNmFkaXF6a2N4",
    "category": "officers",
    "description": "termination-secretary-company-with-name-termination-date",
    "filedOn": "2026-08-18"
  }
}

And a lead-gen row:

{
  "companyNumber": "SC900284",
  "companyName": "CONTENT CREATOR COACH AI LTD",
  "eventType": "incorporation",
  "summary": "New company incorporated in Glasgow (SIC 62012)",
  "filingType": null,
  "effectiveDate": "2026-08-25",
  "officersAffected": [],
  "status": "active",
  "url": "https://find-and-update.company-information.service.gov.uk/company/SC900284",
  "detectedAt": "2026-09-01T01:51:45Z",
  "details": {
    "companyType": "ltd",
    "sicCodes": ["62012"],
    "postcode": "G2 1BP",
    "locality": "Glasgow"
  }
}

Event types

eventType	Fires when
filing	Any new document on the filing history — accounts, confirmation statements, capital changes, strike-off notices. filingType carries the form code.
officer-appointed	A director or secretary is newly appointed.
officer-resigned	An officer's appointment is terminated.
status-change	Company status moves — e.g. active → liquidation, dissolved, administration.
charge	A charge is newly registered, or an existing one changes status (outstanding → satisfied).
incorporation	Lead-gen mode: a company matching your SIC filter was newly incorporated.

Input options

Input	Type	Default	What it does
apiKey	string (secret)	—	Required. Your free Companies House REST API key (see above).
companyNumbers	array	—	Watch-list. 00445790, SC900284, OC301540. All-digit numbers are zero-padded for you, so 445790 also works.
events	multi-select	filings, officers, status, charges	Which changes to report. Fewer events = fewer API requests per company = faster runs.
incorporationFilter	object	—	Lead-gen mode: {"sicCodes": ["62012"], "incorporatedSinceDays": 7}. Requires incorporations in events.
maxItems	integer	500	Cap on changes emitted per run. The rest carry over to the next run.

Both modes can run together in one run.

Update frequency & run time

Companies House updates continuously through the working day, so hourly or daily are both sensible schedules. Run time is governed by the register's rate limit (600 requests per 5 minutes), which the actor paces itself against: roughly 4 requests per company per run with all events selected, so ~100 companies takes well under a minute and a 700-company watch list takes about 20 minutes. Select fewer events to cut the request count per company.

A run where nothing changed emits zero rows and costs only the start fee plus the per-company check — that is the normal, healthy result on a quiet day.

Pricing

Event	Price (USD)	Charged
Actor start	$0.005	Once per run
Change detected	$0.01	Once per change emitted to the dataset
Company checked	$0.0003	Once per watched company compared to its baseline

Watching 100 companies daily with a handful of changes a day costs a few cents per run. You are only charged for changes actually pushed to your dataset.

Notes and limits

• Officers are read from the register's public officer list. Dates of birth are deliberately not collected — only the month/year the register itself publishes is available, and this actor does not put it in your dataset.
• The register's has_charges profile flag is unreliable (some companies report false while holding 136 charges), so the actor checks the charges endpoint itself rather than trusting the flag.
• A company number that is not on the register is logged and skipped — one bad number never kills a run.
• A rejected API key stops the run immediately with an instruction that names the fix, rather than silently returning nothing.
• Data is Crown copyright, published by Companies House under the Open Government Licence.

Maintenance

Schema checked weekly against the live register. Field names within a major version are additive-only: new fields may appear, existing ones keep their names, types and meaning.

Changelog

• 0.1 — First release. Watch-list mode (filings, officers, status, charges) and lead-gen mode (new incorporations by SIC code), fair cross-company budgeting, client-side rate limiting.