How do I find UK companies by SIC code, and what are the limits?

The short answer

Use the advanced search on Companies House (find-and-update.company-information.service.gov.uk/advanced-search). It lets you filter companies by SIC code alongside criteria such as incorporation date and status, and guides report that you can export up to 5,000 records to CSV, including addresses, SIC codes and registration dates. That gives you a sector list quickly and for free. It does not tell you which of those companies to call this week.

Steps

Open the advanced search. Enter one or more SIC codes. Set the company status to active and, if you want newer firms, set an incorporation date range. Run the search, then download the results. Company profiles also list their SIC codes through the Companies House data, so the code can be checked per company.

The limits of SIC codes

SIC codes describe a company's declared activity at a broad level, so a code rarely matches how a buyer thinks about a market. A software firm and an IT support firm may share a code; a company can hold several. A code may be old, because it describes the business at registration or at its last update. Treat a code as a first filter, then read the company's own website to confirm what it does. Lockley's index holds a count of 5,575,015 active UK companies, and 658,310 of them have a website on record, found and confirmed rather than guessed, so most of any sector list will have no easily readable website.

From a sector list to a call list

A list of every active company with a given code can run to thousands of names. To choose, you need something dated. Typical records are a new charge, a director change, a contract ending, a planning application or a first hire in a function. Each is a reason to call that week. Lockley reads these sources nightly and links each finding to its record, so the short list arrives with the evidence. Compare options in our guide to Companies House search against a sales intelligence tool.

A worked example

Suppose you sell managed IT services to small firms. A SIC filter for computer-related activities, active companies only and incorporated in the last two years, gives you a sector list. Exporting it is quick, but the CSV has no information on who has just grown, hired or borrowed. Reading each website to find out would take days. A better route is to take the sector list as the universe and let dated records choose from it: a first IT hire, a new site, a new charge. The sector tells you who could buy; the record tells you who might buy now.

If you do use the export, remove dormant and recently struck-off names, check that each company has a working website, and keep the date you ran the search, since the register changes daily.

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