Company Registration Number Explained: Where to Find It and How to Use It

Every UK limited company receives a unique company registration number when Companies House approves its incorporation. This number identifies the legal entity on the public register and helps banks, customers, suppliers, government departments and other organisations distinguish it from businesses with similar names.

If you have recently incorporated a UK company, you may be wondering where to find your company registration number, whether it appears on your official documents, and when you need to provide it. You may also be unsure how it differs from your Corporation Tax Unique Taxpayer Reference (UTR), VAT number or Companies House authentication code.

A company registration number (CRN) is the official identifier assigned to a company by Companies House. It normally remains the same even if the company changes its name, moves to a different registered office or changes directors. This guide explains what a CRN means, how to find it, where to display it, how organisations use it and which common mistakes to avoid.

What Is a Company Registration Number?

A company registration number, commonly abbreviated to CRN, is a unique reference assigned to a company when it is incorporated at Companies House. It identifies the registered legal entity rather than the business's trading name, its owner or its tax account.

For example, imagine that you establish Northstar Digital Ltd to provide software development services. Companies House assigns the company a registration number when the incorporation is approved. That number remains associated with the legal entity even if you later change its name to Northstar Software Ltd. The CRN helps people find the correct company record and verify basic details such as:

• The company's registered name and current status.
• Its incorporation date.
• Its registered office address.
• Its directors and other recorded officers.
• Its confirmation statement and accounts filing history.
• Other information available on the Companies House register.

The number is particularly useful when two businesses have similar names or when a company trades under a brand that differs from its registered legal name.

What does a UK company registration number look like?

For many companies registered in England and Wales, the CRN consists of eight characters, usually numbers. However, the format varies according to the company's legal form and registration jurisdiction.

Some company numbers contain letters or prefixes. Companies registered in Scotland and Northern Ireland may have different formats from companies registered in England and Wales. Do not assume that every valid company number must contain exactly eight digits. Use the number shown on the company's incorporation certificate or official Companies House record.

Where Can You Find Your Company Registration Number?

There are several reliable ways to locate your CRN. If you have just formed a company, start with your incorporation documents. If you are checking another business, use the Companies House public register.

1. Your certificate of incorporation

The certificate of incorporation is one of the easiest places to find the company registration number. Companies House issues the certificate when it successfully incorporates the company. It records the registered company name, company number, incorporation date and other relevant details.

If you used a company formation agent, the agent may have sent you the certificate by email or made it available through an online dashboard. Search your email for terms such as "certificate of incorporation", "Companies House" or your registered company name. You should also check any company documents folder maintained by your formation provider.

2. The Companies House register

You can find the CRN of a UK company through the official Companies House service. To find a company's number:

1. Open the Companies House company search service.
2. Enter the registered company name or another relevant search term.
3. Select the correct company from the results.
4. Check the company overview and confirm that the name and other details match.
5. Record the company number shown on the official record.

If you are searching for a supplier, customer or potential business partner, check the company's status and registered details rather than relying on the name alone. A similar name does not necessarily mean you have found the correct legal entity.

3. Your formation agent or company management account

If you incorporated your company through an agent, the company number may be included in your welcome email, incorporation pack or online company management dashboard.

For example, a founder using a UK company formation and management platform such as IncorpUK may keep the incorporation certificate and key company details in one place, depending on the service provided. However, the official Companies House record remains the best place to verify the number if you cannot locate your original paperwork.

4. Existing company documents

Your CRN may also appear on business documents, including invoices, purchase orders, contracts, letters and other company records. For UK companies, certain statutory business documents and websites must display specified company information. The exact requirements depend on the type of company and document. If you need to confirm the number, use an official record rather than copying it from an old document that might contain an error.

How Do You Use a Company Registration Number?

A CRN is useful whenever someone needs to identify your registered company accurately. It is not a password or proof that the company is financially sound, but it is an important reference for administration and due diligence.

Opening a business bank account

Banks and electronic money institutions commonly request company details when a business applies for an account. The CRN helps the provider identify the legal entity on the Companies House register. You may also be asked for the certificate of incorporation, details of directors and beneficial owners, proof of identity, information about business activities and evidence of the source of funds.

Providing the correct CRN helps establish which company is applying, but it does not guarantee that an application will be approved. Each provider has its own eligibility, compliance and risk-assessment requirements.

Registering for tax

When dealing with HM Revenue & Customs (HMRC), you may need to provide your company details, including the CRN in circumstances where it is requested. However, the CRN is not the same as your company's Corporation Tax UTR. HMRC uses the UTR to identify the company for Corporation Tax purposes. Keep both numbers available and check which identifier a form or service actually requires.

Filing company information

Companies House uses the CRN to connect filings and correspondence to the correct registered entity. You may need it when dealing with matters such as:

• Filing annual accounts.
• Submitting a confirmation statement.
• Updating company information.
• Checking filing deadlines and company status.
• Reviewing the company's public filing history.

The CRN helps identify the company, but it does not replace the authentication code or other credentials that may be required to authorise an online filing.

Working with suppliers and customers

A company registration number can help business partners confirm the identity of the legal entity they are contracting with. For example, a supplier may receive an order from a brand name that differs from the name of the company making the purchase. Checking the CRN and registered company details can help establish which legal entity is responsible for the transaction. This is particularly useful when dealing with new customers, overseas partners or businesses that operate multiple brands under one registered company.

Completing due diligence

Investors, lenders, professional advisers and potential buyers may use a CRN to access a company's public record. They can review information such as its filing history, registered officers and accounts where available. This may form part of a broader assessment of the business.

A CRN alone does not prove that a company is active, profitable, trustworthy or free from legal disputes. It is a starting point for verification, not a substitute for proper due diligence.

Does a UK Company Have to Display Its Registration Number?

Yes. UK companies must include specified company information on certain business documents and websites. For business letters, order forms and websites, the required information generally includes:

• The company's registered name.
• Its company registration number.
• Its registered office address.
• The part of the UK in which it is registered.
• The fact that it is a limited company, usually indicated by its full registered name ending in “Limited” or “Ltd”.

These requirements help customers and other organisations identify the legal business they are dealing with. See the official GOV.UK guidance on company stationery and promotional material.

Should you put the CRN on invoices?

Invoices are among the business documents for which company disclosure rules are relevant. Make sure your invoice template includes the company's correct legal name and any information required for that document.

For a practical approach, include the CRN and registered office address in your invoice footer, alongside other required business details. This also makes it easier for customers to verify the company. Remember that a company's registered name and its trading name may differ. If you use a brand name, make the legal identity of the company clear where required.

Company Registration Number vs Other Business Numbers

One of the most common mistakes new founders make is treating every number issued by a government department as interchangeable. They are not.

For example, if a bank asks for your company registration number, do not provide your Corporation Tax UTR instead. If a Companies House service requests an authentication code, entering the CRN will not authorise the filing. Keep these details in a secure company records folder and label each one clearly.

Does a Company Registration Number Change?

Generally, the CRN stays the same throughout the life of the company, even when important details change.

If the company changes its name

A company may change its registered name, subject to the relevant Companies House requirements. The new name does not create a new legal entity, so the company normally keeps its existing CRN.

If the company changes its registered office

Moving the registered office does not usually change the CRN. You must, however, notify Companies House through the appropriate process so that the public record remains accurate.

If the company changes directors or shareholders

Changes to directors, shareholders or people with significant control do not normally result in a new company number. The relevant company records and Companies House filings must still be updated where required.

If the company is dissolved

A dissolved company does not become a new company simply because its old registration number remains visible on the public register. If the company is later restored, it is generally restored as the same legal entity, rather than being issued a completely new identity. If you intend to resume a business after dissolution, check the restoration requirements before making assumptions about the company's status or ability to trade.

Common Company Registration Number Mistakes to Avoid

A CRN is straightforward to use, but a few mistakes can cause unnecessary delays.

1. Confusing the CRN with the UTR. They are issued for different purposes. Check the wording of the form or request before providing a number.

2. Omitting leading zeros or letter prefixes. Enter the complete number exactly as it appears on the official register. A shortened or altered number may fail to identify the correct company.

3. Copying a number from an unverified source. A supplier's email signature or an old document may contain an error. Verify important company details on the Companies House register.

4. Assuming a CRN proves that a company is trustworthy. A registration number confirms an identifier, not financial health, creditworthiness or regulatory approval. Check the company's status, filing history and other relevant evidence.

5. Forgetting required business disclosures. Make sure your website, business letters and order forms contain the required company information. Review templates whenever the registered company name or office address changes.

6. Sharing security codes unnecessarily. Your CRN is a public identifier, but your Companies House authentication code is a confidential filing credential. Do not treat them as equivalent.

Frequently Asked Questions

1. How many digits are in a UK company registration number?

Many UK companies have an eight-character CRN, often consisting of eight digits. Some company types and registration jurisdictions use letter prefixes, so the exact format can vary.

2. Is a company registration number public information?

Yes. The CRN appears on the public Companies House register and is intended to help identify the registered company. You can search for it using the company's name.

3. Can I find my company registration number online?

Yes. Use the official Companies House company search service, search for your registered company name and check the company overview.

4. Do sole traders have a company registration number?

Sole traders do not receive a Companies House CRN simply by starting a business. A sole trader may have tax references or other business identifiers, but these are different from the registration number issued to a company incorporated at Companies House.

5. Is my company registration number the same as my VAT number?

No. The CRN identifies the company on the Companies House register. A VAT number is issued by HMRC after VAT registration and is used for VAT-related purposes.

6. Does my company registration number change if I change my company name?

Usually not. The company keeps its CRN when its registered name changes because the legal entity remains the same. Companies House issues the relevant certificate confirming the new name.

7. Can someone misuse my company registration number?

The CRN itself is public information, so knowing it does not normally give someone control over your company. However, fraudsters may use public company details in impersonation attempts. Protect confidential credentials, monitor your Companies House record and investigate unexpected changes.

8. Must I include my CRN on my company website?

UK company disclosure rules generally require the registration number, registered office address, registration jurisdiction and limited-company status to appear on the website, alongside the registered company name. Review the official GOV.UK guidance for the applicable requirements.

Conclusion

Your company registration number is one of the most important identifiers you receive when incorporating a UK limited company. It connects your business to its official Companies House record and helps banks, suppliers, customers and government departments identify the correct legal entity.

You can usually find it on your certificate of incorporation, through your formation agent or on the Companies House public register. Once you have it, use the full number accurately on relevant business documents and keep it distinct from your Corporation Tax UTR, VAT number and Companies House authentication code.

For founders operating internationally, keeping company details organised from the outset can make routine administration and verification easier. Maintain a secure record of your incorporation documents, verify information through official sources and review your business disclosures whenever company details change. These simple habits help you present a consistent, professional and compliant business identity.