Data

Company data is public data, so we keep it easy to reuse. There's no API key and nothing to sign up for: every link below is a plain HTTP GET.

Every company

A single CSV listing every company on the register, live and dissolved, one row per company:

/data/companies.csv

It has two columns, 5,762,249 rows and is about 200MB, so give it a minute.

company_number,name
00445790,TESCO PLC
SC314764,APUC LIMITED
13648401,VK SWIFTCLEAN SERVICES LTD

company_number is the Companies House number, including the SC, NI and OC prefixes, and name is the registered name as filed, in capitals. Dissolved companies are in there alongside live ones, and the rows come in no particular order — sort them yourself if you need to. Everything else we hold about a company — type, status, incorporation and dissolution dates, SIC codes, registered office, officers, owners and accounts — is one GET away on its own page.

A single company

Use a row from the CSV to build the URL for any company: /company/{company_number}. Each company page is also available in other formats by adding an extension:

.json

Full structured record: registered details, officers, PSCs, accounts history and corporate group.

.md

The same information as Markdown, handy for feeding to an LLM.

For example, for Tesco PLC:

/company/00445790
/company/00445790.json
/company/00445790.md

The pages hanging off a company serve JSON at the same URL too, and so do people, addresses, SIC codes and corporate groups:

/company/00445790/officers.json
/company/00445790/psc.json
/company/00445790/accounts/{yyyy-mm-dd}.json
/company/00445790/accounts/{yyyy-mm-dd}.pdf
/company/00445790/network.json
/person/{id}.json
/person/{id}.md
/address/{id}.json
/sic/{code}.json
/sic/{code}/rss.xml
/group/{id}.json

network.json is the graph behind the network explorer, bounded so it stays loadable: depth 2 at most, 250 nodes at most, and fan-outs wider than 50 edges collapsed into a hub node you can expand. The rss.xml feeds carry newly incorporated companies for a SIC code.

OpenCompanies is an independent project and is not affiliated with Companies House. The official register remains the authoritative source: where a figure here looks wrong or out of date, Companies House's own entry takes precedence. Data is reused under the Open Government Licence v3.0.