Companies House for Sales: The Free UK Data Most Founders Ignore
How to use free Companies House data for B2B prospecting: new directors, share allotments, new companies and filings that tell you when to reach out.
Outrun8 min read
Companies House is the UK's official register of companies, and everything on its public register is free to search. For sales, it's a reliable source of timing signals: new directors, new share allotments that point to a funding round, newly incorporated companies and changes of address. Check it against your ideal customer profile (ICP), follow the companies you care about, and you'll often spot a reason to get in touch before it shows up in the news.
Most founders doing their own sales lean on news and job boards for timing. Both are useful, but both are things a company chooses to publish. Companies House is different: limited companies have to file certain changes by law, within set deadlines. That makes it one of the few prospecting sources where the data turns up whether or not anyone wrote a press release.
This guide covers what's on the register, which filings matter for sales, how to check them and how to write a message that doesn't feel odd to receive.
What Companies House gives you for free
Companies House says its Find and update company information service makes all of the public data it holds on companies available free of charge, and you don't need to register to view it. For any company you can see, among other things:
- basic details, including company type and registered office address
- the nature of business, as SIC codes
- company status (for example, active or dissolved)
- when accounts and the confirmation statement were last filed, and when the next ones are due
- the full filing history, with images of the documents
- current and resigned officers
- insolvency information
The same data is available through a free public API, which matters once you want to check more than a handful of companies.
The filings that work as buying signals
A routine confirmation statement rarely tells you much. These are the filings worth watching.
New directors
When someone becomes or stops being a director, the company must tell Companies House within 14 days. So a new appointment appears on the register quickly.
A new director often means change: a new finance lead reviewing suppliers, a new operator brought in to scale a team, or a founder adding experienced people after a raise. New leaders tend to arrive with a remit and some appetite to fix things, which is exactly when a relevant offer gets a hearing.
Share allotments (form SH01)
When a UK limited company issues new shares, it has to file a return of allotment of shares (SH01) within one month of allotting them. New shares are often how a funding round lands on paper, so an SH01 can reveal a raise that was never announced publicly.
Treat it as a hint, not proof. Shares can be issued for other reasons, such as employee schemes or restructures. But a fresh SH01 at a growing company that also has new job posts is a strong combination. For how to approach a company after a raise, see why funding rounds are the best time to reach out and how to find companies that just raised funding.
Newly incorporated companies
If you sell to brand-new businesses (formation services, banking, accounting, insurance, payroll, websites), the incorporation date is the signal. The Companies House API's advanced company search lets you filter by incorporation date range, SIC codes, location, company type and status. That's a quick way to build a list of, say, new software companies registered in Manchester last week.
Changes of registered office
A new registered office address can mean a move, an expansion or just a new accountant. On its own it's weak, but next to new job posts it can suggest a company growing into a new space.
Accounts and filing dates
The register shows when each company's next accounts are due. Private companies normally have 9 months from the end of their financial year to file. If you sell accounting, bookkeeping or finance tools, an approaching deadline is a natural, low-pressure reason to get in touch. Filed accounts can help you check fit, though small companies can leave out the profit and loss account.
How to check Companies House without it becoming a chore
Start with fit, not filings
A brilliant signal from a company that will never buy from you is still a waste of time. Decide who you're looking for first. If you haven't written that down yet, our guide to defining your ICP in 15 minutes will get you there. SIC codes, location and company age are all fields you can filter on directly at Companies House, so make sure your ICP includes them.
Follow the companies you care about
Companies House runs a free Follow service. Once you're signed in, you can select "Follow this company" and it will email you when a new filing has been accepted, with a link to the document. For a short target list, it's the simplest setup there is.
Use the API once your list gets long
Following hundreds of companies by email gets noisy fast. The REST API allows up to 600 requests in a five-minute period, and there's also a streaming API that pushes changes to you as they happen. Either way, you'll need someone comfortable writing a small script, plus somewhere to store what you've already seen.
Combine it with other signals
Companies House is strongest as one input among several. A filing tells you something changed; job posts, news and public posts tell you what the company plans to do about it. Stacked signals, such as a share allotment followed by three sales hires, are far more convincing than any single filing. Our guide to what buying signals are covers the full set, and hiring signals from job posts goes deeper on the most common companion signal.
Turning a filing into a good first message
Nobody wants to feel watched. The register is public, but "I saw your SH01" is an odd way to open an email. A few rules help:
- Reference the change, not the form. "Saw you've brought in a new finance director" reads naturally. "I noticed form AP01" doesn't.
- Lead with the problem the change creates. A new director usually inherits a to-do list. Say how you help with something likely to be on it.
- Be careful with unannounced rounds. If a raise only appears on the register, don't congratulate them on it. Use it to decide who to contact and when, then lead with a relevant problem.
- Keep it short and give an easy out. In the UK, the ICO's guidance on business-to-business marketing covers the basics: identify yourself, keep it relevant to the person's role and offer a simple way to opt out.
Limits worth knowing
Companies House data is only as useful as your reading of it.
- It covers UK-registered companies. If your market is global, it's one source among many.
- Filings lag reality. Deadlines give companies days or weeks to file, so the register confirms change rather than predicting it.
- Not every filing means intent. A new director could be a replacement, and new shares could be an option scheme. Check context before you act.
Let the register come to you
Checking Companies House alongside job boards, funding news and X every morning works, until a busy week arrives and the routine slips.
Outrun does that checking for you. Set your ICP once, or describe your ideal customer in plain English and let AI turn it into fields. Every weekday morning at 7am in your timezone, you get a digest of leads showing a fresh buying signal, in your inbox (or Slack/Telegram on Growth and up). UK Companies House changes are part of the mix, alongside new job posts, funding and news and public posts on X. Each lead comes with a why-now line and a contact.
If you'd like to see which UK companies matching your profile changed something this week, start a 7-day free trial at outrun.so.
FAQ
Is Companies House data free to use?
Yes. Companies House makes the public data it holds on companies available free of charge through its Find and update company information service, and you don't need to register to view it. There's also a free public API for checking companies programmatically.
Which Companies House filings are useful for sales?
The most useful are new director appointments, share allotments (form SH01, which can reveal funding rounds), new incorporations, changes of registered office and upcoming accounts deadlines. Each suggests something has changed at the company.
How quickly do changes appear on Companies House?
It depends on the filing. Director changes must be reported within 14 days and share allotments within one month, so the register usually confirms a change shortly after it happens rather than in advance.
Can I get alerts when a company files something?
Yes. Companies House's free Follow service emails you when a filing from a company you follow has been accepted. For larger lists, the API and streaming API let you check changes automatically.
Is it okay to mention Companies House filings in a cold email?
Mention the change, not the filing. A short question about a new finance director's plans reads naturally, while quoting form numbers can feel like surveillance. Be especially careful with funding rounds that were never announced.
