How to Build a UK Prospect List with Companies House Data

Every UK limited company has to file information with Companies House – and most of it is free to search. For B2B sales teams, that makes it one of the best starting points for a prospect list: official, up to date and searchable by industry and location.

This guide shows how to use Companies House data to build a targeted list, where the gaps are and what to do before anyone picks up the phone.

What Companies House can tell you

For each registered company you can usually find:

• company name, number, status (active, dormant, in liquidation) and date of incorporation;
• registered office address;
• up to four SIC codes describing the company's activities;
• current and past directors and other officers;
• filed accounts, and the type of accounts filed;
• people with significant control.

What it will not give you is phone numbers, email addresses, headcount or the name of the person who buys your kind of product. Those need to come from elsewhere.

Three ways to get the data

1. Advanced search

The Companies House search service includes an advanced company search where you can filter by company status, type, incorporation date, location and SIC code. It is ideal for small, focused lists – for example active limited companies with a particular SIC code in a single county.

2. Free bulk data

Companies House publishes a free monthly snapshot of basic data on all live companies. It is a large download, but once loaded into a spreadsheet tool or database it lets you filter the whole register at once – by SIC code, postcode, incorporation date and accounts category.

3. The API

For ongoing prospecting, the free Companies House API lets you pull company profiles, officers and filing history automatically. It is a good way to spot trigger events, such as a new director appointment, and feed them into your CRM.

Using SIC codes to target an industry

SIC codes are five-digit codes from the UK Standard Industrial Classification. Some examples B2B teams often use:

• 62012 – Business and domestic software development
• 62020 – Information technology consultancy activities
• 69201 – Accounting and auditing activities
• 70229 – Management consultancy activities other than financial management
• 25620 – Machining
• 49410 – Freight transport by road

Search for several related codes rather than one, and test them: you will quickly see which codes return the companies you actually want.

Know the limits of the data

• SIC codes are self-declared. Companies choose their own codes, and many pick broad ones such as “other business support service activities”. Expect to miss some good prospects and include some poor ones.
• The registered office is not always the trading address. Many companies use their accountant's or a formation agent's address, which can distort regional targeting.
• Not every business is a company. Sole traders and ordinary partnerships are not on the register, although LLPs and limited partnerships are.
• Groups and dormant companies. One business can have several registered entities. Filter out dormant companies and decide whether to target the parent or the trading subsidiary.
• Size is only a rough signal. The type of accounts filed – micro-entity, small or full – hints at size, but it is no substitute for headcount or revenue data.

From company list to prospect list

1. Filter by SIC codes, status, location and accounts type.
2. Check fit by reviewing the website of each company, or a sample if the list is large.
3. Find the buyer. Directors are a starting point for small firms; in larger companies the buyer is often a department head who is not on the register.
4. Add contact details from the company website, switchboard research or a reputable data provider.
5. Screen every phone number against the Corporate TPS and TPS before calling – see our guide to Corporate TPS rules.
6. Document your lawful basis. Directors' names are personal data, so UK GDPR applies; read how legitimate interests works for B2B prospecting.

Building and maintaining lists takes time. If you would rather start with a researched, screened list and booked meetings, see how we handle market research and targeting.