What is a company registration number (CRN)?

The moment your company is incorporated, Companies House assigns it a Company Registration Number (CRN) – and from that point on, it follows your business everywhere. You’ll need it to open a business bank account, register for taxes, sign contracts, and file your annual accounts.

It appears on your company’s public record and serves as the official proof that your business legally exists. Without it, many of the organisations you’ll deal with – banks, HMRC, suppliers – won’t be able to verify who you are.

If you’ve just formed a limited company or LLP and aren’t sure where to find your CRN, what it looks like, or when you’ll need to use it, this guide covers everything you need to know.

Why your CRN matters for compliance and verification

Once a company is incorporated, the company registration number becomes its primary legal identifier. Companies House uses the CRN to connect the business to its public record, statutory filings and compliance deadlines. Even if the company changes its name, the CRN remains the same and continues to link the entity to its incorporation history.

The CRN also allows banks, suppliers, government bodies and customers to confirm business identity. Because company names can be similar, the registration number provides certainty and reduces the risk of administrative errors when opening accounts, submitting filings or confirming company details.

The CRN also appears in company documentation and filings, where key information, such as directors, shareholders, and persons with significant control (PSCs), is recorded.

How to get a company registration number

1. You receive a company registration number automatically once Companies House completes your company’s incorporation. It isn’t something you apply for separately – it’s generated as part of the registration process.
2. The number is generated as part of the UK company formation process and first appears on your certificate of incorporation. Once issued, it becomes your company’s permanent legal identifier.
3. CRNs can’t be chosen or customised. Companies House assigns them based on the registration sequence, the jurisdiction of incorporation, and your company type.
4. Online incorporations are typically processed within 24 hours. Once approved, the CRN and certificate of incorporation will be issued to you electronically.
5. To obtain a CRN, your limited company must be registered with Companies House – either directly or through a formation agent. Regardless of the route taken, the CRN is always issued by Companies House.

How to find your company registration number (CRN)

Most founders need the CRN early on, often when opening a business bank account, registering for tax or making their first Companies House filing. There are a few reliable ways to check.

Finding your CRN online

The quickest way to find your CRN is on the Companies House public register. Search your company name and open the company profile – your CRN appears directly beneath the registered name.

You don’t need to log in to access this information. The register also allows you to confirm other key company details, which can be useful when checking a supplier, customer or your own company record.

Finding your CRN on official documents

The CRN appears on the certificate of incorporation and on statutory correspondence from Companies House. You may also see it on certain compliance documents, such as accounts or confirmation statement paperwork, depending on how you file and how your records are stored.

If you manage company administration through an online account, the Online Company Manager can also display the company registration number within the company record.

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Different CRN formats explained

A CRN usually has 8 digits or 2 letters followed by 6 digits. The format depends on the type of entity and where it is incorporated. If you’re unsure whether a number looks correct, verify it on the Companies House register rather than relying on the format alone.

The table below shows how company registration number formats vary by jurisdiction and entity type across the UK.

Limited partnerships use similar prefixes (LP, SL, NL), but most founders will encounter CRNs for limited companies or LLPs.

Who needs a CRN?

A CRN is issued only to businesses and organisations registered at Companies House. Eligible entities include private limited companies, public limited companies (PLCs), companies limited by guarantee, LLPs and limited partnerships.

Do sole traders get a CRN?

Sole traders and general partnerships don’t have a CRN because they don’t incorporate with Companies House. A CRN is only issued to entities incorporated at Companies House, such as limited companies and LLPs.

Instead, sole traders register directly with HMRC for Self-Assessment and operate as individuals rather than as separate legal entities. This means there is no separate company record at Companies House and no company registration number.

If a sole trader later decides to form a limited company, a CRN will be issued at the point of incorporation.

Using your CRN

A CRN is required across compliance, tax and day-to-day administration. If an organisation needs to identify your company precisely, rather than just by name, the CRN is one of the first references they will request.

Compliance and Companies House administration

Use your CRN when you:

• File confirmation statements and annual accounts
• Change the accounting reference date
• Update the registered office address or SAIL address
• Report new appointments or resignations of directors, secretaries or LLP members
• Update officer details or persons with significant control (PSC) information
• Alter the articles of association
• File company resolutions
• Issue new shares or transfer existing shares
• Report charges or company mortgages
• Apply to strike off or wind up the company

Tax and HMRC

HMRC requires your CRN to:

• Register for Corporation Tax, VAT or PAYE
• File Company Tax Returns, VAT Returns or PAYE reports
• Pay company taxes
• Register for schemes such as the Construction Industry Scheme (CIS)
• Report dormant trading status

Banking, finance and supplier onboarding

Banks and lenders use your CRN to verify that your company is properly registered and to match applications to the correct legal entity. You will typically provide it when you:

• Open a business bank account
• Applying for a loan, overdraft or credit facility
• Enter into leases or finance agreements in the company name
• Set up supplier accounts or trade credit arrangements

Insurers, landlords and other commercial partners also use your CRN to confirm the company’s legal status before entering into formal agreements.

Comparing CRN with other identifiers: UTR, VAT, PAYE and authentication code

Companies have several official identifiers, including a company registration number (CRN), Unique Taxpayer Reference (UTR), VAT number, PAYE reference and Companies House authentication code. Each serves a distinct purpose.

A CRN identifies your company on the Companies House register. Tax and payroll references, such as the UTR, VAT number and PAYE reference, are issued by HMRC and relate specifically to tax reporting and payments.

The table below shows how these identifiers differ by issuing body and primary function.

The company authentication code is private and shouldn’t be shared publicly. The authentication code allows authorised filings to be submitted, but it doesn’t replace the company registration number.

Displaying your CRN

UK disclosure rules require limited companies to display their company registration number on specific business communications and materials. These rules sit alongside other statutory disclosures, including the registered office address.

Legal requirements for CRN display

The Company, Limited Liability Partnership and Business (Names and Trading Disclosures) Regulations 2015 require companies to show their CRN on official company stationery and websites. The purpose is to allow third parties to verify the company’s legal identity quickly and accurately.

You must display your CRN on:

• Letterheads
• Emails
• Faxes
• Order forms
• Compliments slips
• Leaflets and flyers
• Catalogues
• Advertisements
• Websites and other online material

These rules apply to printed, digital and electronic communications. You don’t need to place the CRN on every page of a document or website, but you must make it clearly visible and easy to find.

If a company fails to comply with these disclosure requirements, regulators can fine both the company and its officers.

Best practices for CRN visibility

Many companies go beyond the legal minimum and include their CRN in email footers, website footers and routine correspondence. This speeds up verification checks by banks, suppliers and service providers.

Consistent display reinforces the company’s legal identity and reduces friction during onboarding, compliance reviews and commercial negotiations.

Example: how a business uses its CRN over time

A new founder might first see the CRN on the certificate of incorporation immediately after the company is formed. Within the first few weeks, the founder uses the CRN to register for business bank account, set up bookkeeping and confirm the correct company profile on Companies House.

Within a year, the CRN becomes part of routine compliance. The founder uses it when filing the confirmation statement, submitting accounts and updating company details if the registered office address changes. If the business grows and applies for trade credit or a small loan, the CRN is one of the references lenders and suppliers use to validate the business.

Because of its long-term utility, it is helpful to treat the CRN as a core company identifier, not just an administrative number that matters only at incorporation.

What happens when you change company name?

Changing a company name does not alter the CRN. The number stays the same and continues linking the company to its filing history and public record. Companies House issues a certificate of incorporation on change of name, which shows the old and new names alongside the company number.

Lost your CRN? Here’s how to recover it

You can simply search your company on the public register and read it directly from the company profile.

If you don’t know the exact company name you used at incorporation, check the certificate of incorporation first. Companies House letters should also show the company registration number, so searching your records for the number can be faster than searching by name.

You can also access your CRN through the 1st Formations Online Company Manager. The service is available to everyone, including clients and non-clients. Existing customers can log in to view their company data, including their CRN. Non-clients can create a free account, import an existing company and manage it online.

The Online Company Manager also allows users to update company details, download company documents and report changes to Companies House from one central dashboard.

Common mistakes with your CRN and how to avoid them

You can avoid common CRN mistakes by using the number consistently and understanding where it’s required. The most frequent errors include:

• Confusing the CRN with HMRC identifiers such as the UTR or VAT number
• Relying on the company name alone when completing forms instead of using the CRN to identify the legal entity
• Forgetting to include the company registration number on required communications such as websites, emails or business letters
• Overlooking disclosure requirements – can delay verification checks from banks, suppliers or partners and create avoidable compliance risk.

Ready to incorporate?

A company registration number links your business to its official record, filings and compliance activity. Once incorporated, your CRN becomes part of everyday administration, from banking and tax registration to statutory updates.

If you’re ready to form a limited company, 1st Formations can handle the incorporation process for you. Once Companies House approves your application, your CRN and certificate of incorporation are issued electronically – often within 24 hours.

Our online formation process is simple, fully digital and designed to get your business up and running quickly. You’ll receive your CRN as soon as incorporation completes, along with access to ongoing company management tools to help you stay compliant.

Start your company today and secure your company registration number without delay.