This guide is maintained as a current resource for July 2026 and covers only the laws of England and Wales. Information is for general guidance, not legal advice. Consult a qualified solicitor for advice specific to your situation.
Company incorporation number explained in UK law: what it is, what it identifies, how it is used, where to find it, and how it differs from other business identifiers such as UTR and VAT numbers. Clear guide to Companies House registration and company identity.
A company incorporation number, commonly called a Company Registration Number (CRN), is the unique identifier assigned to a business when it is incorporated in the United Kingdom. It is issued by the registrar of companies and is used to distinguish one registered company from every other legal entity on the public register. In England and Wales, this register is maintained by Companies House.
The incorporation number is central to how UK company law identifies legal entities. It is used across filings, public records, tax administration, banking, and compliance processes. Unlike a company name, which can be changed or duplicated, the incorporation number remains fixed for the entire life of the company.
What a Company Incorporation Number Is
A company incorporation number is a unique alphanumeric code assigned at the point of registration. It confirms that a company has been legally formed under the Companies Act 2006 and exists as a separate legal entity.
Key characteristics include:
- Issued only upon incorporation at Companies House
- Unique to each company or LLP
- Permanent for the life of the entity
- Used as the primary identifier on official records
In practice, the incorporation number functions as the company's legal reference point across all official systems.
What the Incorporation Number Identifies
1. Legal existence of the company
The incorporation number confirms that a business is registered as a legal entity. This is particularly relevant for limited companies and limited liability partnerships (LLPs), which have separate legal personality from their owners.
Only incorporated entities receive a CRN. Sole traders and ordinary partnerships do not have one because they are not registered as separate legal persons at Companies House.
2. The exact entity on the public register
Company names are not unique. Multiple businesses can have similar or identical names, and companies can change their names over time. The incorporation number removes this ambiguity.
It identifies:
- The specific company record on the Companies House register
- Its filing history and statutory documents
- Its current status (active, dissolved, in liquidation, etc.)
This makes the number the most reliable reference when verifying a business.
3. The company's lifecycle record
The incorporation number is used to track the company throughout its existence, including:
- Incorporation date
- Director appointments and resignations
- Confirmation statements
- Annual accounts filings
- Dissolution or liquidation records
Even if a company changes its name multiple times, the incorporation number remains unchanged.
4. Regulatory and compliance identity
The incorporation number is used by public authorities and institutions to link records relating to the same company, including:
- Tax records with HM Revenue & Customs
- Company filings with Companies House
- Banking and financial verification processes
- Regulatory compliance checks
This ensures consistent identification across different legal and administrative systems.
Format of a UK Incorporation Number
The format depends on where the company is registered and the type of entity. Common examples include:
- England and Wales: 8 digits (e.g. 12345678)
- Scotland: prefix “SC” followed by numbers (e.g. SC123456)
- Northern Ireland: prefix “NI” followed by numbers (e.g. NI123456)
- Older or special cases may include different formatting structures
Regardless of format, each number remains unique within the UK register.
Where the Incorporation Number Is Found
A company's incorporation number is publicly accessible and typically appears on:
- Certificate of incorporation (issued at formation)
- Official correspondence from Companies House
- The public register entry for the company
- Business stationery such as invoices and letters
It is commonly required when dealing with banks, accountants, suppliers, and public authorities.
Incorporation Number vs Other Business Identifiers
The incorporation number is often confused with other identifiers. Each serves a different legal function:
Company Registration Number (CRN)
- Issued by Companies House
- Identifies the legal company entity
Unique Taxpayer Reference (UTR)
- Issued by HMRC
- Used for corporation tax administration
VAT Registration Number
- Issued by HMRC
- Used for VAT reporting and compliance
PAYE Reference
- Used for payroll and employee taxation
The incorporation number is the only identifier that confirms legal incorporation status.
Why the Incorporation Number Matters in Practice
Business verification
The incorporation number is used to confirm whether a company exists and is properly registered. It is often the starting point for due diligence in:
- Contracting
- Lending and credit checks
- Supplier onboarding
- Investment assessments
Fraud prevention and transparency
Because company names can be misleading or duplicated, the incorporation number is a key tool for identifying legitimate entities and detecting impersonation.
Administrative efficiency
Government systems and professional services rely on the number to avoid confusion between similarly named businesses.
Common Issues and Misunderstandings
1. Name changes do not affect the number
A company can rebrand multiple times, but its incorporation number remains constant. This allows continuity in legal and financial records.
2. Dissolved companies may still appear in records
Even after dissolution, historical records may still be accessible for verification purposes, although availability can vary depending on the age of the company.
3. Not all businesses have one
Unincorporated businesses, such as sole traders, do not have incorporation numbers because they are not registered as separate legal entities.
Key Takeaways
A company incorporation number is the permanent, unique identifier assigned to a UK company or LLP upon registration with Companies House. It identifies the legal entity itself, not just its name, and is used across all official filings, regulatory systems, and verification processes. The number remains unchanged throughout the life of the company and is essential for distinguishing one business from another within the UK legal framework.
