Type a company registration number into the gov.uk search bar and you get more useful information in ten seconds than most due diligence checklists ask for. It's free, it's public, and almost nobody outside finance and legal teams actually uses it before signing a contract or sending a deposit.
Start with the number itself
Every company formed through UK Company Incorporation gets an eight-character registration number the moment Companies House approves it. English and Welsh companies get eight digits. Scottish companies start with SC, Northern Irish ones with NI, and there are separate prefixes for limited liability partnerships and overseas companies with a UK presence. If someone gives you a number that doesn't match the format for the country they claim to be registered in, that's worth a question before you go any further.
The number should appear on invoices, contracts, and the company's website footer. If a business you're dealing with doesn't quote it anywhere and won't provide it when asked, treat that as a signal rather than an oversight. Legitimate companies use the number constantly because banks, suppliers, and HMRC all ask for it.
Searching the register
Go to the Companies House service on gov.uk and search either by company name or by the number directly. Searching by number is more reliable, because company names can be similar or reused after a previous company with the same name has dissolved. Type in the CRN and you land on the company's public record.
That record tells you the company's status: active, dissolved, in liquidation, or in the process of being struck off. It shows the incorporation date, the registered office address, the nature of the business (via SIC codes), and a filing history going back to formation. You can open individual documents, including annual accounts and confirmation statements, as PDFs.
Check the incorporation date against what the company claims about its history. A company website boasting "over 20 years of experience" attached to a registration date from 2021 is either describing a predecessor business badly or stretching the truth. Neither is a good sign on its own, but it's worth asking about.
What the filing history tells you
Look at how recently the confirmation statement was filed. It's due annually, and Companies House shows the exact date. A statement that's overdue means the company hasn't confirmed its basic details for over a year, which sometimes signals a business that's stopped operating properly, even if it hasn't formally closed.
Accounts filing history matters more. Companies House imposes automatic penalties for late accounts, and persistent late filing is public information sitting right there on the record. A pattern of last-minute or overdue filings, year after year, tells you something about how the business is run even if you can't see the numbers inside those accounts. For smaller companies exempt from filing full accounts, you'll usually see abbreviated or micro-entity accounts instead, which is normal and not a red flag by itself.
Directors and people with significant control
The record lists current and past directors, along with their month and year of birth (not the full date, for privacy reasons) and nationality. Cross-check the named directors against who you're actually dealing with. If someone claims to be a director but doesn't appear on the register, or resigned according to the filing history, that's a direct contradiction worth raising before you proceed.
The persons with significant control section shows who owns or controls 25% or more of the company. This is where beneficial ownership gets disclosed, and it's useful for spotting shell structures or checking whether the person negotiating with you actually has authority to make decisions.
Registered office versus trading address
A registered office is a legal requirement, not proof of where a company actually operates. Plenty of legitimate businesses use a Virtual Office Address in UK city centres, London, Manchester, Belfast, as their registered office while trading from somewhere else entirely, or nowhere fixed at all if the business is remote. That's not suspicious on its own. What matters is whether the company responds to correspondence sent there and keeps its filings current. If the registered address comes back as a residential property with dozens of unrelated companies attached to it, that's more worth noting than a professional virtual office address used properly.
Putting it together before you commit
None of this takes more than a few minutes once you know where to look. Pull the CRN, search gov.uk, check the status and filing history, confirm the directors match who you're speaking to, and look at how the registered address is being used. A company that checks out on all of these isn't guaranteed to be trustworthy, but one that fails even one of them deserves a direct question before any money or contract changes hands.