Companies House bulk data: every free download explained

Overview of the free bulk products

Companies House offers four free bulk downloads on download.companieshouse.gov.uk, all unsupported and all under the Open Government Licence v3.0. Sizes below were read from the download pages on 17 October 2026.

What is not on the download site: officers (directors and secretaries), charges and filing history. Officer data is available in bulk only on request from Companies House; everything else comes from the API.

Free Company Data Product

The Free Company Data Product is a monthly snapshot of basic data for live companies, as CSV. It includes company number, name, registered office address, company type and status, incorporation date, SIC codes, accounts category, accounting reference date and the next accounts and confirmation statement due dates. The field list is published as a PDF.

The October 2026 file, BasicCompanyDataAsOneFile-2026-10-01.zip, is 471 MB zipped. Our snapshot of it holds 5,704,712 companies, of which 5,166,057 have the status "Active" and 423,006 "Active - Proposal to Strike off". Dissolved companies are not included, so counting incorporations by year from this file counts survivors only.

Use it for anything that needs the whole register: counts by SIC code or postcode, lists of companies with overdue accounts, or a local lookup table so that you never call the API for a company profile. On 1 October 2026 it showed 93,785 active companies past their accounts due date; see UK companies with overdue accounts for the breakdown.

Accounts data: daily, monthly and historic

The accounts products contain one file per set of accounts filed electronically, which Companies House puts at about 75% of the 2.2 million accounts it expects each year. Paper and PDF filings are not included, and many large groups file that way.

Daily files

A new daily file, such as Accounts_Bulk_Data-2026-10-16.zip (74.9 MiB), is added each morning from Tuesday to Saturday. Tuesday's file covers Saturday, Sunday and Monday. Each daily file stays on the site for 60 calendar days and is then removed, so a job that runs less often than every two months will miss data unless it also reads the monthly files.

Monthly and historic files

Monthly files hold the last 12 months, for example Accounts_Monthly_Data-September2026.zip at 3.1 GB. In the last two years, December and September were the largest months. Older months move to the historic page, which goes back to 2008; 2008 and 2009 are single yearly files of 602 MB each.

File names inside the ZIP

Each entry is named like Prod224_2602_10623966_20250531.html. The third part is the company number and the last part is the balance sheet date, not the filing date. Prod224_2602 is an internal run reference. The extension tells you the format: .html for iXBRL, .xml for older plain XBRL, .zip for a package of iXBRL documents.

PSC snapshot

The PSC snapshot contains every person with significant control reported to Companies House, as JSON. It is overwritten every morning before 10am with data to the end of the previous day, and comes as one file or 33 parts of about 70 MB each. Every record carries the company number, so you can join it to the company data snapshot.

For changes during the day, Companies House also runs a PSC streaming API. The snapshot plus the stream gives you a live ownership register without polling the REST API company by company.

What is not available in bulk

Not everything has a bulk equivalent, and it helps to know before you design a pipeline.

• Officers. Not on the download site. Companies House supplies officer snapshots and update files on request, through its developer forum.
• Filing history and documents. Only through the API and the Document API, one company at a time.
• Charges and insolvency details. API only.
• Dissolved companies. Not in the company data snapshot.
• Profit and loss for small companies. Most small companies do not file one. Micro-entity accounts were the latest filing of 32.4% of active companies on 1 October 2026.

Loading it efficiently

The company data CSV loads into SQLite or Postgres in minutes. The accounts archives are the heavy part: tens of millions of small files and about 255 GB of compressed history before you parse anything.

What worked for us across about 37 million iXBRL filings:

1. Read files straight from the ZIP with a streaming reader instead of extracting millions of small files to disk.
2. Parse in parallel, one process per core. A simple Python parser handles about 300 files a second on one laptop core.
3. Store one row per company and balance sheet date, and keep the most recently published version when the same period arrives twice.
4. Record which archive each row came from, so that a parser fix can be replayed on exactly the affected files.

The parsing itself is where most errors come from. See how to parse iXBRL accounts in Python for code that resolves contexts correctly.

Bulk vs API vs hosted

Choose by how many companies you need and how fresh the data must be.

Fetching one profile for every company through the API takes about 33 days on a single key at the standard rate limit. The same data is one 471 MB download.

If you want the parsed figures without running the pipeline, our API serves them from the same accounts files; a free key with 50 requests a month is on the developer docs page.

Sources

• Free Company Data Product, checked 17 October 2026
• Accounts data product, daily files, checked 17 October 2026
• Accounts data product, monthly files, checked 17 October 2026
• Accounts data product, historic files, checked 17 October 2026
• PSC snapshot, checked 17 October 2026

FAQ

Is Companies House bulk data free?

Yes. The company data snapshot, the accounts files and the PSC snapshot are free to download and reuse under the Open Government Licence v3.0, including commercially, with attribution. Companies House notes that the products are not supported, so there is no help desk for file format questions. Officer bulk data is not on the download site and has to be requested.

How far back do the bulk accounts files go?

To 2008. The historic page has a yearly file for 2008 and one for 2009, then one file per month from January 2010. The last 12 months are on the monthly page and the last 60 days on the daily page. Each file contains only accounts filed electronically, so earlier years have fewer companies.

Does the bulk data include turnover and profit?

Only where the company filed them. Small companies may file abridged or filleted accounts without a profit and loss account, and micro-entities show a short balance sheet. Large companies that do report turnover often file PDF accounts, which are not in the iXBRL files at all. Expect turnover to be missing for most rows.

How do I get directors' data in bulk?

Request it from Companies House. Officer appointment snapshots and update files are not on the public download site; Companies House supplies them on request, through the bulk data requests section of its developer forum. For a smaller number of companies, the officers endpoint of the public API is the simpler route.

Sources: Companies House register and accounts data (Open Government Licence v3.0), legislation.gov.uk and GOV.UK guidance where linked. This page is general information, not legal, tax or credit advice. Spotted an error? Email info@globalmindsetmarketing.co.uk.