Last Updated on July 7, 2026 by Joy Kyalo
A company registration number (CRN) is the unique identifier assigned by Companies House when a UK limited company is incorporated. It remains the same throughout the company’s lifetime.
If a bank asks for your company registration number, a supplier wants to verify your business, or you are completing a government form, there is very little room for guesswork. This number is one of the basic identifiers attached to a legally registered company, and using the wrong one can slow down onboarding, compliance checks, and routine administration. So, what is a company registration number? Put simply, it is the unique number assigned to a company when it is officially incorporated by the relevant government authority.
For UK businesses, this number is issued by Companies House at the point of incorporation. It stays with the company for its entire life, even if the business changes its name. That permanence is what makes it useful. It allows regulators, banks, accountants, clients, and service providers to confirm that the company exists as a distinct legal entity.
Quick Answer
A company registration number (CRN) is the unique number issued by Companies House when a UK limited company is incorporated. It identifies the company throughout its lifetime and is used for banking, tax, statutory filings, and business verification.
Key Takeaways
- Every UK limited company receives a unique company registration number.
- The registration number never changes, even if the company changes its name.
- You can find it on your Certificate of Incorporation and Companies House record.
- A company registration number is different from a UTR, VAT number and PAYE reference.
What is a company registration number used for?
A company registration number is mainly used to identify a limited company in official records. Think of it as the company’s fixed reference number. A trading name can change, a registered office can move, and directors may come and go, but the registration number remains the same.
In practice, you will see it used across a wide range of business activities. It may be requested when opening a business bank account, applying for credit, setting up payment services, entering supplier agreements, dealing with accountants, or completing tax and compliance documents. It also appears on public registers, which helps third parties verify who they are dealing with.
That matters commercially as well as legally. If you are trying to build trust with customers, investors, or overseas partners, being able to provide accurate registration details quickly signals that your operation is properly established and professionally managed.
Where can you find a company registration number?
In the UK, the easiest place to find it is on the company’s certificate of incorporation. This is the official document issued when the company is formed. The number will also appear on the public company record held by Companies House.
Most established businesses also include the number in routine documentation. You may find it on invoices, order forms, business letters, statutory notices, and sometimes on the company website. UK company law requires certain business information to be displayed in specific places, so it should not be difficult to locate if the company is operating correctly.
If you are checking your own records and cannot find it, that does not necessarily mean anything is wrong. Early-stage businesses sometimes misplace formation documents, especially if incorporation was handled by an agent or previous adviser. In that case, the public register is usually the quickest way to retrieve the correct number.
Where Is the Company Registration Number on the Certificate of Incorporation?
Your company registration number appears on the Certificate of Incorporation issued by Companies House. It is usually displayed near the company name and incorporation date and consists of eight characters, depending on the company type and jurisdiction.
What does a company registration number look like?
In the UK, a company registration number is usually 8 characters long. For many companies, it is made up entirely of numbers. In some cases, it includes letters at the beginning, depending on the type of entity and where it was incorporated.
For example, companies registered in England and Wales often have an 8-digit numeric number. Scottish, Northern Irish, and certain other entity types may have letter prefixes. The format can vary, but the key point is that it is unique to that company.
This is where businesses sometimes get caught out. They assume the number must follow one standard pattern, then treat anything different as an error. In reality, the format depends on the jurisdiction and entity type. What matters is that the number matches the official record.
Company registration number vs tax numbers
One of the most common points of confusion is the difference between a company registration number and a tax reference. They are not the same thing.
A company registration number identifies the legal entity on the incorporation register. A tax number identifies the business for tax purposes with the relevant tax authority. In the UK, that might include a Unique Taxpayer Reference, a VAT number, or a PAYE reference. Each serves a different administrative purpose.
This distinction matters because forms, applications, and banking checks may ask for one but not the other. Entering a VAT number where a company registration number is required can create delays. The same applies if an overseas founder assumes an EIN, business number, or other foreign tax identifier is interchangeable with a UK incorporation number. It is not.
For businesses operating across the UK, USA, and Canada, this becomes even more important. Each country has its own registration and tax systems, and the terminology is not always aligned. A professionally managed setup should keep these identifiers clearly separated and easily accessible.
Company Registration Number vs Other Business Numbers:
| Identifier | Purpose | Issued By |
|---|---|---|
| Company Registration Number (CRN) | Identifies the company | Companies House |
| Unique Taxpayer Reference (UTR) | Corporation Tax | HMRC |
| VAT Number | VAT reporting | HMRC |
| PAYE Reference | Payroll taxes | HMRC |
Does every business have a company registration number?
No. Whether a business has a company registration number depends on its legal structure.
In the UK, limited companies and limited liability partnerships receive official registration numbers when they are formed. Sole traders do not have company registration numbers because they are not incorporated as separate legal entities. Ordinary partnerships also do not usually have one unless they are registered in a structure that requires formal incorporation.
This is an important distinction for founders choosing a business structure. Incorporation brings legal separation between the business and its owners, but it also brings filing responsibilities, public disclosure rules, and formal record-keeping obligations. The registration number is part of that framework.
If you are trading without incorporation, you may still have tax references and other registrations, but you will not have a company registration number in the same sense as a limited company.
Which Businesses Have a Company Registration Number?
| Business Type | Company Registration Number? |
|---|---|
| Limited Company | Yes |
| Limited Liability Partnership (LLP) | Yes |
| Sole Trader | No |
| Ordinary Partnership | Usually No |
Why the number matters beyond paperwork
It is easy to think of a company registration number as an administrative detail, but it plays a wider role in business credibility and operational efficiency.
First, it supports due diligence. Banks, partners, landlords, payment providers, and procurement teams regularly verify company details before approving applications or contracts. A correct registration number helps them confirm the company’s legal status, incorporation date, and registered office.
Second, it supports compliance. Many filings and statutory processes depend on the correct company identifier. If records are inconsistent, you increase the risk of rejected forms, delayed submissions, or avoidable follow-up from regulators and service providers.
Third, it supports continuity. Businesses evolve. They rebrand, enter new markets, appoint new directors, and change office arrangements. Through all of that, the registration number remains the stable reference point tying the company back to its legal record.
For international operators, that stability is especially useful. If you are setting up a UK entity as part of a wider expansion plan, your registration number becomes one of the key details that underpins banking, tax registration, compliance administration, and third-party verification.
What is a company registration number in an international context?
The basic idea is the same across many jurisdictions: an official number is assigned when a company is formed and entered on a government register. The detail, however, varies by country.
In the UK, the number comes from Companies House. In other countries, the issuing authority and naming convention may be different. Some founders refer to all of these as company numbers, registration numbers, or business numbers interchangeably. That is understandable, but it can cause confusion when you are handling cross-border setup.
For example, a company registered in the USA may have a state registration number, a federal tax number, and local licensing records. In Canada, federal and provincial registrations may sit alongside tax accounts and business numbers. These identifiers can overlap in day-to-day use, but they are not always the same thing.
That is why internationally active businesses benefit from having their formation and administration managed in a structured way. If the wrong identifier is used on a banking application or compliance form, simple setup tasks can become unnecessarily time-consuming.
Common mistakes businesses make
The most frequent mistake is confusing the company registration number with a tax number. Close behind that is using an old or incorrect company name when searching for the number, especially after a rebrand.
Another issue is failing to display company information correctly on official documents. For incorporated UK businesses, certain details should appear on correspondence and business materials. Missing or inconsistent information can create a poor impression and, in some cases, raise compliance issues.
There is also a practical mistake that affects many overseas founders. They complete incorporation, receive the number, and then move straight to trading without organising their records. Later, when a bank, payment provider, or accountant asks for incorporation details, they are forced to search through emails and attachments at the last minute. That slows everything down.
A more reliable approach is to keep your registration number, certificate of incorporation, tax references, registered office details, and statutory records stored together from day one. If your setup is being handled by a trusted provider such as BusinAssist, that administrative foundation is much easier to maintain.
When should you use your company registration number?
You should use it whenever official company identification is required. That usually includes incorporation records, statutory filings, formal correspondence, identity checks, and commercial applications where the legal entity needs to be verified.
You do not need to quote it in every casual business interaction, but you should be ready to provide it quickly. If your business is applying for finance, entering a new supplier relationship, or establishing a presence in a new country, delays often come from missing or inconsistent core information rather than from the underlying transaction itself.
For a founder, that means the number is not just something to file away after incorporation. It is part of the operating infrastructure of the company.
Common Mistakes to Avoid
| Mistake | Correct Approach |
|---|---|
| Using a VAT number instead of a CRN | Use the Companies House registration number. |
| Assuming the number changes after a company name change | The registration number remains the same. |
| Confusing a UTR with a CRN | They are different identifiers. |
| Not keeping incorporation documents | Store them with your statutory records. |
A company registration number is, at heart, a simple identifier. But in practical terms, it is one of the small details that keeps business setup, compliance, and commercial activity moving cleanly – and those details tend to matter most when speed and credibility are on the line.
FAQs:
Q: What is a company registration number?
Ans: A company registration number (CRN) is the unique number issued by Companies House when a UK limited company is incorporated. It identifies the company throughout its lifetime.
Q: Is a company registration number the same as a UTR?
Ans: No. A company registration number identifies your company on the Companies House register, while a Unique Taxpayer Reference (UTR) is issued by HMRC for tax purposes.
Q: Can a company registration number change?
Ans: No. Once Companies House issues a company registration number, it remains the same even if the company changes its name or registered office address.
Q: Do sole traders have a company registration number?
Ans: No. Sole traders are not incorporated businesses, so they do not receive a company registration number. Limited companies and LLPs do.
Q: How can I find my company registration number?
Ans: You can find it on your Certificate of Incorporation, Companies House public record, business correspondence, or by searching your company on the Companies House register.
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The BusinAssist Editorial Team has 15+ years of experience writing about small business and company formation in the UK, Canada, and the USA. We simplify complex processes and provide practical insights to help entrepreneurs succeed. Business Assist with BusinAssist – your partner for business success.