If you are setting up a UK limited company, you will encounter one number almost immediately: your company number. It may look like a simple administrative reference, but it is one of the most important identifiers attached to a UK company. Banks, customers, suppliers, accountants, government departments and Companies House use it to identify the correct legal entity.

A company can change its name, registered office, directors and business activities over time, but its company number generally stays with it throughout its existence. So, what exactly is a company number, where can you find it, and how is it different from a VAT number or tax reference? This guide explains everything founders need to know.

What Is a Company Number?

A company number, also known as a Company Registration Number (CRN), is a unique identification number assigned to a company when it is incorporated with Companies House. It identifies the specific legal entity registered at Companies House. For example, a company might be registered as:

ABC Digital Ltd
Company number: 12345678

The number belongs to the company itself, not to the individual director. If ABC Digital Ltd later changes its name to XYZ Digital Ltd, its company number will normally remain the same. This makes the company number an important way of identifying the business independently of its name.

Why Is a Company Number Important?

A company number provides a reliable reference for identifying a legal entity. Company names can change. Businesses can have similar names. Companies can move registered offices or appoint completely different directors. The company number provides continuity. It can be used when:

• Searching for a company on Companies House
• Opening a business bank account
• Dealing with HMRC
• Completing business contracts
• Communicating with Companies House
• Filing company documents
• Conducting due diligence
• Applying for certain licences
• Dealing with accountants or solicitors
• Verifying a supplier or customer
• Identifying a company in legal or commercial documents

For a founder, remembering the company number is often more useful than remembering the exact date the company was incorporated.

What Does a UK Company Number Look Like?

The format depends on where the company is registered and the type of entity. For many companies registered in England and Wales, the company number consists of eight digits, such as: 12345678

However, not every UK company number follows exactly the same format. Companies registered in Scotland, Northern Ireland and certain specialist registers can have different prefixes or formats. For example, a Scottish company may have a number beginning with SC, while a Northern Irish company may have a number beginning with NI. The prefix can therefore provide useful information about the company's registration jurisdiction.

Does the Company Number Contain Information About the Company?

Sometimes the format gives an indication of where the company was registered or the type of entity involved. However, you should not try to infer too much from the number itself. The safest approach is to search the number on Companies House and confirm the company's official details.

When Does a Company Get Its Company Number?

A company receives its company number when it is successfully incorporated. The number is issued by Companies House, the UK's registrar of companies. Once the incorporation application has been accepted, the company becomes a registered legal entity and receives its company number along with its incorporation documentation. The Certificate of Incorporation contains the company's:

• Registered name
• Company number
• Date of incorporation
• Type of company
• Registered jurisdiction

The certificate is therefore one of the easiest places to find your company number after incorporation.

Is a Company Number the Same as a Registration Number?

Yes, in normal UK company terminology, company number, company registration number (CRN) and Companies House registration number generally refer to the same identifier. You may see different wording depending on who is asking for it. For example: "Please provide your company registration number." or: "Enter your Companies House number." or: "What is your CRN?" These requests normally refer to the same company identifier.

How Do You Find Your Company Number?

There are several straightforward ways to find it.

1. Check Your Certificate of Incorporation

Your Certificate of Incorporation should show the company number. If you formed the company recently, this is usually the quickest place to look.

2. Search Companies House

You can search for your company using its name. The company profile will display the company number alongside other information.

3. Check Your Company Documents

Your company number may appear on documents such as:

• Confirmation statements
• Accounts
• Company resolutions
• Incorporation documents
• Official Companies House correspondence

4. Check Your Company Website

UK companies are generally required to display certain corporate information on business websites and documents, depending on the circumstances. Many businesses display their company number in the website footer. For example:

ABC Digital Ltd | Company No. 12345678 | Registered in England and Wales

This makes it easier for customers and business partners to identify the legal entity behind the website.

Is a Company Number the Same as a VAT Number?

No. This is one of the most common points of confusion for new business owners. A company number identifies the legal entity registered with Companies House. A VAT registration number identifies a business that is registered for Value Added Tax with HMRC. They serve different purposes. For example:

Company: ABC Digital Ltd
Company number: 12345678
VAT number: GB123456789

A company can have a company number without being VAT registered. Not every company needs to register for VAT. VAT registration depends on the business's circumstances and the applicable VAT rules.

Is a Company Number the Same as a UTR?

No. A Unique Taxpayer Reference (UTR) is a separate number issued by HMRC for tax purposes. This means a UK company may have several important identifiers.

These numbers should not be substituted for one another. If a bank asks for your company number, entering your VAT number or UTR will not provide the information it needs.

Is a Company Number the Same as a Tax Number?

No. Companies House and HMRC perform different functions. Companies House is responsible for maintaining the register of companies. HMRC administers taxes. Your company number therefore identifies your company for corporate registration purposes, while your UTR identifies it within HMRC's tax system. This distinction becomes particularly important for new founders because several government identifiers can arrive around the same time.

Does a Company Number Change?

Generally, no. A company's number is intended to be a permanent identifier. For example:

ABC Consulting Ltd
Company number: 12345678

If the company changes its name to:

ABC Global Consulting Ltd

the company number normally remains:

12345678

This is one reason the company number is so useful for due diligence. A business cannot simply change its corporate history by changing its name.

What If a Company Changes Its Registered Office?

The company number normally stays the same. The company can move from one registered office to another while retaining the same legal identity.

What If the Directors Change?

Again, the company number remains the same. The company is a separate legal entity from its directors. Directors can resign and new directors can be appointed without creating a new company number.

Can a Company Have More Than One Company Number?

A single legal company normally has one company number. However, the same entrepreneur can own or operate multiple companies, and each separate company will have its own number. For example:

ABC Holdings Ltd — 12345678
ABC Trading Ltd — 87654321
ABC Properties Ltd — 11223344

Even if the same person owns all three businesses, they are separate legal entities. This distinction matters for contracts, banking, accounting, taxation, liabilities and corporate governance.

Can Two Companies Have the Same Company Number?

No. A company number is intended to uniquely identify a registered company within the relevant Companies House register. Two separate companies cannot legitimately share the same company number. If you encounter two businesses claiming to use the same company number, check the information directly against the official Companies House register.

Can a Company Number Be Reused?

Company numbers are generally treated as unique identifiers associated with the relevant company. A dissolved company's number is not simply reassigned to a newly incorporated business as though it were a new identifier. This helps preserve the integrity of the historical corporate record. For researchers and businesses conducting due diligence, it means a company number can be an important reference for tracing a company's history.

Do Sole Traders Have a Company Number?

Generally, no. This is because a sole trader is not incorporated as a separate company at Companies House. A sole trader can have a UTR and other business identifiers, but they do not automatically receive a Companies House company number simply because they operate a business. This is one of the key differences between operating as a sole trader and incorporating a limited company.

What About Partnerships?

Ordinary partnerships are not the same as limited companies and do not necessarily have a Companies House company number. However, Limited Liability Partnerships (LLPs) are registered with Companies House and receive a registration number. The exact identifier therefore depends on the legal structure.

Where Should You Display Your Company Number?

UK companies have legal obligations concerning the company information they display on business documents and communications. Depending on the circumstances, company information may need to appear on items such as:

• Business letters
• Order forms
• Invoices
• Websites
• Emails
• Certain promotional materials
• Other formal business communications

The exact requirements can vary depending on the company's structure and circumstances. The safest approach is to make sure your company number and other required corporate information are consistently presented on official business materials. For example:

IncorpUK Ltd
Company number: 12345678
Registered in England and Wales
Registered office: [address]

A company should not assume that simply displaying its trading name is enough.

Why Company Numbers Matter for Online Businesses

For ecommerce businesses, SaaS companies, consultants, agencies and other digital businesses, the company number provides an additional layer of transparency. Consider an online store operated by: Global Homeware, A customer may not immediately know whether this is:

• A sole trader
• A limited company
• A foreign business
• A brand operated by another company

If the website identifies the legal entity and company number, the customer can search Companies House and verify the business. This can be especially valuable for international customers who are unfamiliar with the company.

Company Number and International Founders

For non-UK residents, the company number is particularly useful because it provides a clear UK corporate identifier even when the founder lives overseas. A founder based in Nigeria, Canada, the UAE, India or another country may operate a UK company remotely.

The company number allows banks, payment providers, suppliers and customers to distinguish the UK company from the founder personally. However, having a company number does not automatically provide:

• A business bank account
• VAT registration
• Stripe approval
• Tax residency
• A UK immigration status
• Permission to operate a regulated activity

The company number proves that the company is registered; it does not prove that the business has every other approval it may need. This distinction is important for global entrepreneurs. IncorpUK is a UK company formation and management platform for global founders, providing incorporation and ongoing company-management resources alongside registered office support, banking guidance, payment gateway guidance and other business infrastructure. For international founders, understanding the role of the company number is one of the basics of managing a UK company remotely.

Can You Search a Company Using Its Number?

Yes. In many cases, searching by company number is actually more reliable than searching by name. Company names can be similar or can change. For example, if you search for: ABC Trading, you might see multiple businesses. If you search for: 12345678, you can identify the specific company associated with that number. Once you locate the company, you can review publicly available information such as:

• Company status
• Registered office
• Directors
• PSCs
• Filing history
• Accounts
• Previous names
• Confirmation statements

What Can You Learn From a Company Number?

The number itself does not tell you everything about a company. Instead, it acts as a key that lets you access the company's Companies House record. Using the number, you can potentially establish:

Whether the company exists

You can confirm whether a company is registered.

Whether it is active

The Companies House record will indicate its current status.

When it was incorporated

You can check the company's incorporation date.

Who manages it

Current and former directors can be reviewed.

Who controls it

PSC information can provide insight into significant control.

How the company has changed

The filing history can reveal changes to the company's name, address, officers and other corporate information. This makes the company number useful for basic due diligence.

What Should You Do If You Lose Your Company Number?

Do not panic. You can usually find it quickly through the Companies House search service. Search using the company's registered name and check the correct company profile. You can also check your:

• Certificate of Incorporation
• Confirmation statement
• Company accounts
• Formation documents
• Accountant's records
• Company management platform
• Official correspondence

If your company has changed its name, search using its current or previous name.

Company Number vs Company Name: Which Is More Important?

Both matter, but they serve different purposes. The company name is how the legal entity is identified publicly and commercially. The company number is its unique corporate identifier. A company can change its name. Its company number provides continuity. For this reason, if you are signing a contract, checking a supplier or conducting due diligence, it is good practice to identify the legal entity by both name and company number. For example: ABC Global Ltd, company number 12345678, is much more precise than: ABC Global, The second could refer to a brand, trading name or completely different legal entity.

Frequently Asked Questions

What is a company number in the UK?

A company number is a unique identifier assigned by Companies House when a company is incorporated. It is also commonly called a Company Registration Number or CRN.

Is a company number the same as a CRN?

Yes. "Company number", "company registration number" and "CRN" are commonly used to describe the same Companies House identifier.

Where can I find my company number?

You can find it on your Certificate of Incorporation, Companies House company profile, confirmation statements, accounts and other corporate documents.

Does a company number change when the company name changes?

Generally, no. A company normally keeps the same company number even when its registered name changes.

Is a company number the same as a UTR?

No. A company number is issued by Companies House, while a UTR is an HMRC tax reference.

Is a company number the same as a VAT number?

No. A company number identifies the company at Companies House. A VAT number identifies a business registered for VAT with HMRC.

Do sole traders have a company number?

Generally, no. Sole traders are not incorporated companies and therefore do not automatically receive a Companies House company number.

Can I search a UK company by its company number?

Yes. Searching the Companies House register by company number is one of the most precise ways to locate a specific company.

Does every UK business have a company number?

No. Company numbers are associated with companies and certain registered entities. Sole traders and ordinary partnerships do not automatically have Companies House company numbers.

Conclusion

A company number is the unique corporate identifier assigned to a company when it is registered with Companies House. It is much more than a number on a Certificate of Incorporation. It provides a consistent way to identify a legal entity even when its name, registered office, directors or business activities change. For founders, the key points are simple:

• Your company number is issued when your company is incorporated.
• It is commonly called a CRN or company registration number.
• It is different from your VAT number and HMRC UTR.
• Your company normally keeps the same number throughout its existence.
• You can use it to find your company on Companies House.
• Other people can use it to investigate your company's public record.
• It should appear on relevant business documents and communications where required.
• Having a company number does not automatically mean that your business has every tax, banking, regulatory or payment approval it may need.

For anyone forming a UK company, particularly a founder operating from outside the UK, understanding the company number is one of the first steps towards understanding how the UK's corporate system works. Once you know the difference between your company number, UTR, VAT number and other business identifiers, managing your company's administration becomes considerably easier.