Published: 27 July 2026 10:46 am  Author: Oliver Stanley

What Is a Company Registration Number and Where Do You Find It?

If you’ve ever filled in a form, applied for business insurance, or tried to open a bank account for your company, you’ve probably been asked for your company registration number. It’s one of those details everyone assumes you have to hand: until the moment you need it and can’t remember where you put it.

A company registration number (CRN) is the unique code that Companies House assigns to every company incorporated in the UK. It’s how the register tells your business apart from every other one, including any other company that happens to share your name. Below, we’ll cover exactly what a CRN is, what it looks like, where to track yours down in under a minute, and where the law says you have to display it.

What is a company registration number?

A company registration number is the unique identifier Companies House gives a company the moment it’s incorporated. You’ll also see it called a “company number,” “registration number,” or “Companies House number” – these all mean the same thing.

Every company on the UK register, private or public, gets one. It’s issued once, it never changes, and no two active companies share the same number. Even if you rename your company, sell it, or restructure it entirely, the CRN stays exactly as it was on day one. That permanence is the whole point: it lets anyone (a bank, a supplier, a court, a due diligence team) confirm they’re looking at the same legal entity over time, regardless of what it’s currently trading as.

It’s worth being clear about who this applies to. Sole traders and ordinary partnerships don’t have a CRN, because they aren’t registered at Companies House at all. Only limited companies, limited liability partnerships (LLPs), limited partnerships, and a handful of other entity types (like companies formed by royal charter) get one.

What does a CRN actually look like?

A UK company registration number is eight characters long. For most private and public companies incorporated in England and Wales, that’s simply eight digits, for example 12345678.

Some entity types and jurisdictions get a two-letter prefix followed by six digits instead. The prefix tells you where or how the company was formed:

• SC – company incorporated in Scotland
• NI – company incorporated in Northern Ireland
• OC – limited liability partnership registered in England and Wales
• SO – limited liability partnership registered in Scotland
• NO – limited liability partnership registered in Northern Ireland
• LP / SL / NL – limited partnerships (England & Wales / Scotland / Northern Ireland)
• FC / SF / NF – overseas companies with a UK presence (England & Wales / Scotland / Northern Ireland)
• RC / SR / NR – companies incorporated by royal charter (England & Wales / Scotland / Northern Ireland)
• GE / GS / GN – European Economic Interest Groupings (England & Wales / Scotland / Northern Ireland)

So SC123456 is a Scottish company, OC987654 is an English or Welsh LLP, and a plain 07654321 is a standard England and Wales limited company. None of these prefixes are optional extras or branding, they’re baked into the number itself.

Company registration number vs. other business numbers

It’s easy to muddle a CRN with the other reference numbers a company collects, especially early on. They’re issued by different bodies for different reasons:

A CRN comes from Companies House and identifies the company itself on the register. A Unique Taxpayer Reference (UTR) is a 10-digit number from HMRC, used for Corporation Tax, you’re issued one automatically after registering your company. A VAT number only exists if and when the company registers for VAT, and again comes from HMRC. A PAYE reference is issued by HMRC once you register as an employer.

If someone asks for your “company number” or “registration number,” they almost always mean the CRN from Companies House, not a tax reference. Handing over the wrong one is a common (and easily avoided) mix-up.

Where to find your company registration number

If you need your CRN and don’t have it memorised, here are the fastest places to look, roughly in order of how quickly they’ll get you an answer.

Your certificate of incorporation. This is the document Companies House issued when your company was formed. It states the registered company name, the date of incorporation, and the company number, and it’s usually one of the first documents saved (or forgotten) in a company’s records.

The Companies House register, for free. If you can’t lay your hands on any paperwork, search Companies House’s “Find and update company information” service by company name. It’s free, doesn’t require an account, and returns the CRN along with the registered office address, filing history, and incorporation date. This also works if you need someone else’s CRN, not just your own.

Your confirmation statement or other Companies House filings. Any statutory filing you’ve submitted (confirmation statements, annual accounts, changes of director) will have the CRN printed on it, either on the document itself or in the confirmation email or letter from Companies House.

Official correspondence from Companies House. Letters and emails from Companies House reference your company number, usually near the top.

Your own stationery. As covered below, most companies are legally required to print their CRN on business letters, order forms, and their website, so a quick check of your own website footer or letterhead may save you the search entirely.

Your accounting or company secretarial software. If your firm uses a platform to manage entity records (Kudocs included) the CRN is stored against the company profile and pulled through automatically wherever it’s needed, rather than being something someone has to go and look up.

Where you’re legally required to display it

This is the part that catches people out: showing your CRN isn’t just good practice, it’s a legal requirement for most limited companies under the Companies Act 2006 and the Companies (Trading Disclosures) Regulations 2008.

You must show your company’s registered number, its registered office address, and where it’s registered (England and Wales, Scotland, or Northern Ireland) on:

• business letters
• order forms
• your company website

You also need to spell out that it’s a limited company, usually by using the full registered name including “Limited” or “Ltd.” If you choose to name directors on your stationery, you have to name all of them, not a select few.

Invoices are covered by a separate, more detailed set of rules (which also bring in things like VAT numbers where relevant), so it’s worth checking those requirements specifically rather than assuming the same short list applies.

Skipping this isn’t just a formatting oversight: failing to display the required details is a criminal offence under the trading disclosures regulations, and Companies House and other regulators can and do act on it. In practice, most enforcement starts with a request to correct the omission, but it’s a needless risk for something that takes minutes to fix once you know your CRN.

A quick note on why this matters more now

Companies House has been getting noticeably stricter. Since the Economic Crime and Corporate Transparency Act 2023 came into force, the register has moved from being a fairly passive filing archive to something Companies House actively checks and queries. Identity verification for directors and people with significant control became mandatory from November 2025, and more checks on the accuracy of company data are expected to follow.

For firms managing filings and registers on behalf of clients (law firms, accountants, and corporate service providers among them) that raises the bar on keeping every company’s core details, CRN included, correct and consistent across every document and system you use. A wrong or outdated number on a letterhead, contract template, or client register is a small error with an outsized chance of being noticed at exactly the wrong moment.

This is where a lot of firms find spreadsheets and shared drives start to strain: one client’s CRN typed differently in three different templates, a register that hasn’t been checked against Companies House in months, or a confirmation statement filed with a number nobody double-checked. Kudocs was built to remove that risk by keeping entity data, including each company’s registration number, synced directly with Companies House and consistent everywhere it’s used, so your team isn’t relying on someone remembering to check.

The short version

A company registration number is the permanent, unique code Companies House gives your company on incorporation: eight characters, sometimes with a two-letter prefix depending on where and how the company was formed. It’s different from your UTR, VAT number, or PAYE reference, all of which come from HMRC instead. You can find it on your certificate of incorporation, on any Companies House filing, or in seconds via the free Companies House register, and if you run a limited company, you’re legally required to display it on your letters, order forms, and website.

Once you know where to look, it’s a two-minute job. The trick is not having to look it up more than once, which is exactly the kind of small, recurring admin task that’s worth automating out of your day.