Guide · United Kingdom

What is Companies House?

Companies House is the UK's official registrar of companies: the public record for every British limited company, LLP and CIO. Here is what it holds, how its company numbers work and what you can query.

Updated 28 October 2026

The short answer

Companies House is the executive agency of the United Kingdom government that registers and dissolves limited companies. It operates under the Companies Act 2006 and is part of the Department for Business and Trade (DBT). Every UK limited company, Limited Liability Partnership (LLP), Limited Partnership (LP), Charitable Incorporated Organisation (CIO), and Community Interest Company (CIC) is registered there.

Whenever a UK company is incorporated, files accounts, appoints a director, raises capital, registers a charge, changes its registered office, or is dissolved, Companies House is the public record. They publish the data in three forms: the BasicCompanyData monthly bulk CSV (~5.7M active + recently-dissolved companies), the PSC register daily JSON snapshot (~7M Persons with Significant Control), and a free-tier REST API covering individual company profiles, officers, filing history, and charges.

Reading a UK company number

Every Companies House registration has an 8-character identifier called the company_number. The format encodes the legal-form type:

When you store UK company identifiers, always preserve the leading zeros — Companies House numbers are zero-padded to 8 chars and a database column typed as integer would lose them.

What data Companies House publishes

• BasicCompanyData — monthly bulk CSV. Company name, number, registered address, legal form (CompanyCategory), status, founding date, dissolution date, SIC codes, previous names (up to 10), accounts & confirmation-statement due dates. ~5.7M rows, ~500MB compressed across 7 slices.
• PSC register — daily JSON snapshot of every Person with Significant Control. Individual PSCs include name, partial date of birth (month-precision only), nationality, country of residence, nature of control. Corporate PSCs include name and identification details. ~7M records, ~2GB compressed across 31 slices.
• Filings via REST API — every public filing event: account submissions, confirmation statements, officer appointments & resignations, address changes, capital changes, mortgage charges, dissolution notices. Rate-limited at 600 requests per 5 minutes per API key.
• Officers via REST API — directors, secretaries, LLP members, judicial factors, receivers. Includes appointment date, resignation date, role.
• Charges (mortgages) via REST API — registered legal charges over the company's assets.

Companies House vs. The Gazette

Insolvency events (winding-up petitions, administration orders, CVAs, dissolutions) are not published directly in Companies House — they appear in The London / Edinburgh / Belfast Gazette, the UK's three official journals of record. The Gazette and Companies House cross-reference each other but use different identifiers, so a complete UK risk picture needs both feeds. Prometiam draws on Gazette notices into the /search insolvency endpoint with source_country=GB, alongside Spanish concurso and French procédure-collective records.

What Prometiam gives you on top

Companies House publishes the raw material; the work is turning three differently-shaped sources into one queryable surface. Prometiam serves UK companies, officers, PSC beneficial owners, corporate events, Gazette insolvency notices and GLEIF Legal Entity Identifiers through the same endpoints and the same response shape as every other country the API covers — all behind ?country=GB. Annual accounts as filed are served from the Scale plan, for digitally filed (iXBRL) accounts only. The UK company data API guide walks through the number lookup, officers and PSC, and UK companies that have stopped filing carry a strike-off warning signal. Companies dissolved beyond the bulk product's window are included, so a counterparty that closed two years ago still resolves.

Coverage: UK companies, Persons with Significant Control, officers, appointments, corporate events and GLEIF LEIs. Refreshed daily. Hosted in the EU (Frankfurt).

Querying UK data

Via the Prometiam API, a trial key unlocks endpoints like:

# Search by company number
GET /companies/search?country=GB&company_number=00445790

# Fuzzy name search
GET /companies/search?country=GB&name=tesco

# Full company detail (officers, PSCs, filings)
GET /companies/{id}

# Insolvency / dissolution events from The Gazette
GET /search?country=GB&name=lehman

# Director / PSC appointment history
GET /people/{id}

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FAQ

What is Companies House?
Companies House is the United Kingdom's executive agency that registers and dissolves limited companies, files company information, and makes that data available to the public. It is part of the Department for Business and Trade (DBT) and operates under the Companies Act 2006.

What is a company number?
Every company registered with Companies House has an 8-character company number. Pure numeric numbers (e.g. 00445790) are England & Wales or Scotland. Special prefixes denote special types: SC (Scotland alternative format), NI (Northern Ireland), OC (LLP - Limited Liability Partnership), LP (Limited Partnership), FC (UK establishment of overseas company), OE (Overseas Entity), CE (CIO - Charitable Incorporated Organisation), and others.

What is a PSC (Person with Significant Control)?
A PSC is anyone who owns more than 25% of a UK company's shares or voting rights, or otherwise exercises significant control. Since 2016 every UK company must publish its PSCs in the Companies House register. PSCs can be individuals (natural persons), corporate entities, or other legal persons. Prometiam serves the PSC register for UK companies.

What is a SIC code?
Standard Industrial Classification of Economic Activities — the 5-digit code Companies House uses to classify what a UK company does. UK SIC 2007 (e.g. 62020 = 'Information technology consultancy activities'). Companies can declare up to 4 SIC codes. SIC is the UK equivalent of CNAE in Spain or NAF in France.

How do I query UK companies programmatically?
Use the Prometiam company data API. GET /companies/search?country=GB&company_number=00445790 returns TESCO PLC. GET /companies/search?country=GB&name=tesco does a fuzzy-match search. Free trial: 500 credits over 14 days with a card required and nothing charged for 14 days; Starter (€9.99/month) raises that to 10,000.

Is Companies House part of the UK government?
Yes. Companies House is an executive agency of the UK government, part of the Department for Business and Trade. It registers and dissolves limited companies and publishes the register.

Which government department is Companies House part of?
The Department for Business and Trade (DBT). It operates under the Companies Act 2006.

Is Companies House a registry or a regulator?
It is primarily the registrar: it incorporates and dissolves companies and holds the public record of what they file. Insolvency events are published separately in the Gazette.

Does Companies House only cover UK companies?
It registers companies incorporated in the UK. The register also holds the UK establishments of overseas companies (FC prefix) and overseas entities (OE prefix).

What is the UK equivalent of a French SIREN number?
The company number: an 8-character registration number whose prefix shows the legal form. Always keep its leading zeros.

Why does a UK company number start with OC, SC, NI or LP?
The prefix encodes the legal form or nation: OC is a limited liability partnership, SC a Scottish company, NI a Northern Ireland company and LP a limited partnership. Plain 8-digit numbers are ordinary companies.

Is Companies House data free?
Yes. Companies House publishes the BasicCompanyData product as a monthly free bulk download (~5.7M companies, ~500MB compressed CSV across 7 slices), the full PSC register as a daily snapshot (~7M records, ~2GB JSON), and individual company profiles via a free-tier REST API (600 requests per 5 minutes per key). Filings PDFs are also free.

Why does the bulk product only have ~5.7M companies when CH has issued 17M+ numbers?
The BasicCompanyData bulk product only contains companies that are currently active or recently dissolved. Companies dissolved more than ~6-12 months ago are dropped from the bulk dump but remain queryable individually via the REST API at /company/{number}. Prometiam includes those older dissolved companies, so a counterparty that closed years ago still resolves.

Related reading

• What is BORME? The Spanish equivalent
• What is BODACC? The French equivalent
• SIREN vs SIRET vs NIF — and where company_number fits in
• Insolvency monitoring across Europe (and the UK)