The UK Company Database, Explained: What's Public, What's Not, and How to Use It

A UK company database is a structured, searchable record of the country's companies, built on the public register held by Companies House and usually enriched with extra data. At its core it tells you, for any company, who runs it, who owns it, where it is, what it does and what it has filed. The differences between databases come down to how much they add on top — financials, contact data, ownership mapping, signals — and how easily you can search and export.

The free foundation: Companies House

Everything starts with Companies House, the official registrar. It holds well over five million companies and publishes, free of charge:

• Company name, number, status and incorporation date
• Registered office address and SIC (industry) codes
• Directors and people with significant control (PSCs)
• Full filing history — accounts, confirmation statements, charges and mortgages

This is authoritative data, straight from the source. Its limits are practical: the free interface searches one company at a time, offers little bulk filtering, and is not built for list-building or analysis.

What providers add on top

Commercial databases layer extra value onto that foundation. Common additions include:

• Structured financials — turning filed accounts into comparable figures like turnover, net worth and cash, so you can screen by size or health.
• Credit and risk scores — for checking whether to extend terms to a customer or supplier.
• Contact data — phone numbers and emails appended from other sources (accuracy varies and is the most over-promised feature in the market).
• Ownership and group mapping — connecting parent companies, subsidiaries and shared directors.
• Signals and recency — new incorporations, director changes and filing events surfaced as they happen.

CompaniesIQ sits in this layer, but with a deliberate stance: it is live-only, drawing company data straight from the Companies House API and regional economic indicators from the free Nomis/ONS service, rather than reselling a stale snapshot.

Match the database to the job

Different jobs need different databases:

• Research and market sizing — you want clean industry and regional breakdowns. Pages like technology, financial services or the West Midlands turn the register into a market picture.
• Lead generation — you want recency and tight filtering. See new business leads from Companies House.
• Due diligence and KYC — you want ownership, PSCs and filing history. See who owns a company in the UK.
• Credit decisions — you want financials and scores, ideally with the filed accounts behind them.

Questions to ask before you choose

• Is it live or a snapshot? Stale data quietly costs you — dissolved companies, resigned directors, old addresses.
• Where does each figure come from? A trustworthy provider tells you what is from Companies House, what is modelled and what is third-party. CompaniesIQ publishes this on its sources page.
• Can you filter and export the way you work? By SIC code, region, recency, size.
• What does it cost at your volume? Per-search pricing and unlimited plans suit very different users — compare on pricing.

The bottom line

The "best" UK company database depends entirely on the job. For authoritative core facts, nothing beats Companies House itself. For anything involving lists, filtering, recency or analysis, you want an intelligence layer on top — ideally one that stays close to the live source and is honest about where every number comes from. If you are weighing options, our piece on Companies House search alternatives compares the main routes.