Companies House API alternatives: which UK company data API should you use? (2026)

Quick comparison

The main question is whether you need balance sheet figures as data. If you only need names, status, officers and filing dates, the official API is free and hard to beat.

Every provider in the table builds on the same public source: Companies House accounts, mostly the iXBRL files in the free bulk data. The differences are in parsing quality, history depth, extra data such as credit scores, and price.

Companies House API

The official Companies House API is free, current to the minute and covers profiles, officers, persons with significant control, charges, insolvency and filing history. Its limit is 600 requests per five minutes per key, and Companies House can raise it on request.

What it does not do is return accounts figures. You get a link to each accounts document, and for most electronic filings you can download the iXBRL version and parse it yourself. Large groups often file PDF only. See how to get Companies House financial data as JSON for the full workflow.

Best for: live register data, officers and PSCs, and any project that can live without financial figures or wants to parse them in house.

OpenCorporates

OpenCorporates is a worldwide register of companies with a strong focus on open data and provenance. Its API plans start at £2,250 a year for 500 calls a month (Essentials), then £6,600 a year (Starter) and £12,000 a year (Basic), with enterprise plans on request. Free access is available to open data projects that republish under its share-alike licence, and to journalists, NGOs and researchers through its public-benefit programme.

Its pricing page lists no parsed accounts figures, so for UK financials it is not a substitute for the providers below. We found no official OpenCorporates MCP server, only community-built ones.

Best for: cross-border entity data and corporate networks across many countries.

Endole API

Endole sells a UK company research platform with credit reports, monitoring and an API in the same subscription. A single-user plan is £39 a month, or £25 a month billed annually, and its API page says "starting from £25/month". Endole advertises 10-year financial trends, credit scores and limits, and CCJ, Gazette and charges history. API call limits are not published.

Best for: small teams that want a web app with credit scores and monitoring, plus some API access, in one subscription.

Creditsafe

Creditsafe is an enterprise credit reference agency with full financials, credit scores and limits, monitoring and a company data API. It offers a free API key for testing and development and a free trial of its platform, but production prices are not published; you get a quote from sales.

Best for: credit control and onboarding teams that need scores, limits and international coverage and have a budget for a contract.

Registrum

Registrum is a UK company API and hosted MCP server. Its free plan gives 50 calls a month (15 a day), Web is £9 a month, Pro is £49 a month for 4,000 calls with PSC chain and ownership tracing, and Enterprise is custom. Its get_financials tool returns turnover, net assets, profit and employees parsed from iXBRL, for the current and prior year.

Its MCP server at https://registrum.co.uk/api/mcp works with no key and no sign-up, with small daily caps per tool. That is the lowest-friction way to try a Companies House MCP server today.

Best for: ownership and PSC chains, ECCTA compliance checks, and trying MCP with zero setup.

CompanyStack

CompanyStack is the closest to us in data: it advertises 24.8 million years of accounts for 3.6 million active companies, read from filings since 2008. Its API is free up to 1,000 requests a day (30 a minute), Starter is £29 a month for 10,000 a day and Business £99 a month for 100,000 a day. MCP access is included on all API tiers and needs an API key. The web app has a free tier and Pro at £19 a month.

CompanyStack says plainly that turnover and profit exist for only about 2% of companies, a caveat that applies to every source built on iXBRL accounts.

Best for: high daily volumes on a low budget.

DataLedger

DataLedger, run by DataLedger Ltd in Glasgow, sells UK company financials, ratios and PSC data as an API and as datasets. The API starts with 25 free credits, then Pro at £10 a month for 300 credits and Commercial at £20 a month for 2,000 credits, plus one-off credit packs. Datasets start at £295 for up to 5,000 companies. It publishes an open-source MCP server that runs locally and needs a DataLedger key.

Best for: one-off datasets for a list of companies, and pay-as-you-go API use.

FinUK

FinUK, from Raq.com, offers JSON financials for over 4 million companies with up to 17 years of history. Its home page says "free trial then from £14/month" with 10 free lookups, while its pricing page lists a Pro plan at £90 a month for 9,000 requests; check the current tiers before you commit. We found no MCP server.

Best for: long financial histories as JSON in a conventional REST API.

UK Company Data (ours)

UK Company Data covers the full Companies House register and balance sheet figures parsed from about 37 million iXBRL accounts filed from 2008 to 2026, for about 7 million companies. One key works for the REST API and the MCP server, which exposes tools for search, lookup, comparison, financial triggers and a watchlist with alerts. Free is 50 requests a month; API Pro is £39 a month for 5,000 requests and a 50-company watchlist; a one-off financial history pack for one company is £9.

Our limits: we show risk bands derived from filed figures, but no credit score, credit limit, CCJs or officer data, and companies that file PDF only (many large groups) have no figures. Responses default to Markdown text designed for AI agents; add format=json to the company, search and alerts endpoints for one JSON field per figure.

We also run data studies on the same dataset, for example that 93,785 active companies were past their accounts due date on 1 October 2026 (overdue accounts statistics).

Best for: AI agents and assistants that need multi-year balance sheets, monitoring alerts and lead signals through MCP. Try it with a free key from the developer docs page.

How to choose

1. You need live status, officers or PSCs: the free Companies House API.
2. You need figures for the whole population: the free bulk accounts files and your own parser, or a dataset from DataLedger.
3. You need credit scores and limits: Creditsafe or Endole.
4. You need high volume cheaply: CompanyStack's free and Starter tiers.
5. You want an AI assistant to answer company questions: Registrum to try with no key, or UK Company Data for history since 2008 and alerts.

FAQ

Is there a free alternative to the Companies House API?

The Companies House API is itself free, so the question is usually about financial figures. Several providers have free tiers that include parsed accounts: CompanyStack allows 1,000 requests a day, Registrum 50 calls a month, DataLedger 25 credits and UK Company Data 50 requests a month. The Companies House bulk accounts files are also free if you parse them yourself.

Which API gives UK company turnover?

Any of the financial APIs here return turnover when the company filed it. Most small UK companies do not: micro-entity and filleted accounts omit the profit and loss account, and CompanyStack puts turnover coverage at about 2% of companies. Large companies that report turnover often file PDF accounts, which iXBRL-based sources cannot read.

Can I use the Companies House API commercially?

Yes. Companies House data is published under the Open Government Licence v3.0, which allows commercial use with attribution. You need to stay within the rate limit of 600 requests per five minutes and must not try to bypass it. The paid providers above charge for their processing and service, not for the data itself.

Which Companies House API alternatives have an MCP server?

Registrum (hosted, no key needed), CompanyStack (included with API plans), DataLedger (self-hosted) and UK Company Data (hosted, free key). There are also many open-source servers that wrap the official API with your own key. See our comparison of Companies House MCP servers.

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.