What is a company registration number (CRN)?

The company registration number (CRN) is issued by Companies House when a new company is officially incorporated (registered). All UK companies are given a unique CRN, sometimes known as a ‘company number’ or a ‘registration number’, for the purpose of identifying the business and confirming its status as a legally incorporated entity.

Company registration numbers are only issued to businesses that are registered at Companies House, such as limited companies and limited liability partnerships (LLPs). Sole traders and traditional partnerships do not receive a CRN, because they aren’t incorporated through Companies House. Instead, they’re registered with HMRC.

What does a company registration number look like?

A Company Registration Number is treated as an eight-character identifier by Companies House. For many companies, this appears as eight digits, for example: 12345678.

The format can vary depending on the type of entity and where it was registered:

• Companies registered in England and Wales usually have eight digits
• Companies registered in Scotland use SC followed by six digits
• Companies registered in Northern Ireland use NI followed by six digits
• Limited liability partnerships may begin with OC, SO, or NC, depending on where they were formed
• Limited partnerships may begin with LP, SL, or NL, depending on where they were formed

On older documents, you may see a company number shown with fewer than eight digits. This doesn’t mean the number is different. In modern use, leading zeros are added, so the identifier always appears as eight characters. For example, a number shown as 12345 would now be written as 00012345.

All of these formats are valid. The prefix or length doesn’t affect how the CRN functions: it simply reflects the entity type and where the business was registered.

Where can I find my company registration number?

You can find your company registration number on your certificate of incorporation, which will have been issued by Companies House as soon as your company was registered.

This certificate will have been sent to you by email and/or by post if you set up a company through an approved company formation agent.

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If you incorporated directly with Companies House, your certificate will have been delivered by email or post, depending on what method of incorporation you used.

Your CRN can also be found on all official correspondence received from Companies House, and it is available to view online by accessing the public register via Companies House Service.

Still can’t find your CRN? 

Don’t panic. As long as your company exists and is registered at Companies House, your CRN is recoverable. 

Start by: 

• Searching the public register using your company’s name 
• Trying any previous names if your business rebranded 
• Searching by registered office address if necessary 

When do I need to use my company registration number?

Your CRN proves your company’s legal identity in many important situations. You’ll be asked for your CRN whenever you need to confirm your company’s status or complete formal processes. For example, you must provide your CRN when:

1. Making changes to your company at Companies House, e.g., changing the registered office address or the name of the company
2. Filing documents at Companies House, such as annual accounts and Confirmation Statements.
3. Issuing (allotting) or transferring shares
4. Registering for Corporation Tax, VAT, or PAYE with HMRC
5. Sending Company Tax Returns, annual accounts, VAT returns, and PAYE reports to HMRC
6. Opening a business bank account and applying for finance

In most formal or legal situations, you’ll often be asked for your CRN rather than just the company name.

Where should I display my company registration number?

UK law requires that limited companies and LLPs make their registered details and certain other information available to the public. As such, limited companies and LLPs must display their CRN on all formal business documents and at all relevant touchpoints. These include:

• Letterheads and order forms
• Invoices and receipts
• Official company emails
• Your company’s website

These requirements are outlined by The Company, Limited Liability Partnership and Business (Names and Trading Disclosures) Regulations 2015.

CRN vs UTR: What’s the difference?

New company owners often confuse a Company Registration Number with a Unique Taxpayer Reference (UTR), but the two relate to different systems. 

Identifier	Purpose	Issued by
CRN	Confirms legal company identity	Companies House
UTR	Tracks tax records and filings	HMRC

A CRN identifies your company on the Companies House register. A UTR, issued by HMRC, is used to track tax records. Because they serve different purposes, one cannot be used in place of the other.

You’ll use your CRN when dealing with Companies House or confirming the company’s legal identity. You’ll use your UTR when handling Corporation Tax, Self Assessment, or other HMRC matters. If a form asks specifically for a CRN, entering a UTR instead will usually result in an error. 

Get support with staying compliant

Your company number is one of the simplest and most important numbers your business will use. From bank applications to tax returns, it validates your status and ensures your filings are linked to the right company. 

Keep your CRN safe, display it where required, and use it any time your legal business identity must be confirmed.

Looking for a smarter way to track your legal documents, filing obligations, and deadlines? Visit the Quality Company Formations homepage to explore services designed to help UK companies stay compliant from day one.