What Numbers and Codes Does a New UK Company Receive?

When you register a limited company in the UK, Companies House issues an official company number and a certificate of incorporation. You may also receive a Corporation Tax reference from HM Revenue & Customs (HMRC), while other numbers and codes become available when you complete additional registrations or apply for specific services.

For new founders, these identifiers can be confusing. A company registration number is not the same as a tax reference, a Companies House authentication code is not a company number, and a VAT number is not automatically issued to every newly incorporated business.

A new UK limited company receives a company registration number when it is incorporated. Other numbers and codes depend on its tax status, identity-verification requirements, employment arrangements and business activities. This guide explains which identifiers you should expect, what each one does, when you receive it and how to avoid common mistakes after incorporation.

1. Company Registration Number (CRN)

The Company Registration Number (CRN) is the official identifier assigned to your company by Companies House when the company is incorporated. It is one of the first details you will receive after successful registration.

What is the company registration number used for?

Your CRN identifies the legal entity on the Companies House register. You may need it when:

• Opening a business bank account.
• Applying for VAT registration.
• Communicating with Companies House.
• Completing company administration and compliance checks.
• Providing company details to suppliers, clients or professional advisers.

Your CRN appears on your certificate of incorporation and the company's public Companies House record. The format depends on the company's registration jurisdiction and type. For many ordinary UK limited companies, it consists of eight characters, often numbers, but some company numbers include letters.

Is the CRN the same as the company name?

No. Your company name can change, subject to the relevant requirements, but the company's registration number normally remains the same throughout its existence. For example, suppose you incorporate Northstar Digital Ltd and receive a company number. If you later change its name to Northstar Software Ltd, the CRN remains the identifier for the same legal entity. Keep the CRN in your company records. It is useful for confirming that you and the organisations you deal with are referring to the correct company.

2. Certificate of Incorporation

The certificate of incorporation is the official document confirming that Companies House has registered your company. It is not a number or code in itself, but it is one of the most important documents you receive when forming a limited company. The certificate normally includes:

• The registered company name.
• The company registration number.
• The date of incorporation.
• The company's legal form and whether it is private or public.
• The jurisdiction in which the company is registered.

Companies House issues the certificate once the incorporation application has been accepted. The certificate is evidence that the company legally exists. You may be asked to provide a copy when opening a bank account, setting up payment services, entering commercial agreements or completing due diligence. Store the certificate securely and keep an accessible digital copy. It is particularly useful if you manage your UK company from another country.

3. Unique Taxpayer Reference (UTR)

A Unique Taxpayer Reference (UTR) is a 10-digit number used by HMRC to identify a taxpayer or organisation for tax purposes. A limited company has its own Corporation Tax UTR, which is different from a director's personal UTR.

When does a new company receive its UTR?

When you register a limited company directly through the standard Companies House service, the company will usually be set up for Corporation Tax at the same time, unless it is dormant.

HMRC generally sends the Corporation Tax UTR to the company's registered office address. It typically arrives around 15 days after registration, although delivery can take longer, particularly for overseas addresses. If the company was not automatically set up for Corporation Tax, or the UTR has not arrived, check the relevant HMRC guidance and take the appropriate steps.

What is the UTR used for?

You may need the company UTR to:

• Access the company's Corporation Tax services.
• Submit a Company Tax Return when required.
• Communicate with HMRC about Corporation Tax.
• Complete certain tax registrations, including VAT registration.

The UTR is a tax identifier, not proof that the company has paid tax or is fully tax-compliant. Important: Keep the company's UTR separate from your personal tax reference. If you are a director who also files Self Assessment returns, you may have a personal UTR as well as the company's Corporation Tax UTR.

4. Companies House Authentication Code

The Companies House authentication code is a six-character alphanumeric code used to authorise certain online filings for a company. It serves a different purpose from the CRN. The CRN identifies the company; the authentication code helps authorise changes and submissions made on its behalf.

How do you get the authentication code?

You may need to request it through the Companies House online filing services. Companies House sends the code by post to the company's registered office, and delivery can take up to 10 working days. Do not assume that the authentication code will arrive with the certificate of incorporation. Plan for it separately if you intend to file company information online.

Why must you protect it?

Anyone who obtains the code may be able to authorise certain online changes to your company's information. Treat it like a confidential security credential. Share it only with an accountant, formation agent or other authorised person who genuinely needs it, and change it if you believe it has been compromised. The authentication code is also different from your Companies House personal code, which relates to an individual's identity verification.

5. Companies House Personal Code

Companies House personal codes are linked to the identity-verification process for individuals who need to verify their identity under the applicable Companies House requirements. Unlike the company authentication code, a personal code belongs to an individual, not to the company.

Who needs a personal code?

Directors and people with significant control may need to verify their identities and provide their personal codes as required by Companies House. If you have already completed identity verification, you can generally find your code through your Companies House account. The way you receive or retrieve it depends on how and when you verified your identity.

For a company with multiple directors, each director must meet the applicable requirements individually. This is particularly relevant to international founders. Incorporating a UK company does not remove the need to complete identity checks where they apply. Remember that a personal code is not the company's CRN, UTR or authentication code. Keep these credentials clearly labelled to avoid confusion when filing documents.

6. SIC Code (Standard Industrial Classification)

A Standard Industrial Classification (SIC) code identifies the type of business activity a company carries out. Unlike a CRN or UTR, a SIC code is not a unique number assigned to your company. You select the appropriate code or codes during incorporation to describe the company's activities.

Why does a SIC code matter?

Companies House uses SIC codes to classify businesses on the public register. The information can help other people understand the company's stated activities. For example, a software development company would select a code appropriate to software-related activities, while a business providing management consultancy would choose a relevant consultancy code.

Choose codes that accurately reflect what the company does. If your business activities change, you may need to update the SIC codes through the appropriate confirmation statement process. A SIC code does not replace a business licence, professional qualification or regulatory authorisation. Selecting a code also does not automatically register your company for tax or VAT.

7. VAT Registration Number

A VAT registration number is a nine-digit number issued by HMRC to a business that has successfully registered for Value Added Tax (VAT). It is not automatically issued to every new UK limited company.

When does a company need a VAT number?

Under the rules applicable in October 2026, a business generally must register for VAT if its taxable turnover for the previous 12 months exceeds £90,000, or if it expects its taxable turnover to exceed £90,000 in the next 30 days alone. Other circumstances can also create a registration obligation, including certain businesses based outside the UK.

A business may also choose to register voluntarily if eligible. After successful registration, HMRC issues a VAT number and confirms the effective date of registration. You must not show VAT as a separate charge on invoices until you have received your VAT registration number, even if your effective registration date is earlier. If you are not VAT-registered, do not invent a number or use your CRN in its place.

8. PAYE Reference and Accounts Office Reference

If your company registers as an employer, HMRC provides identifiers for its Pay As You Earn (PAYE) obligations. Two important references are:

• Employer PAYE reference: Identifies the employer's PAYE scheme.
• Accounts Office reference: Used to identify payments made to HMRC for employer liabilities.

These references are associated with employer registration rather than being issued automatically to every incorporated company.

When will you need them?

You will generally need them if your company employs staff or operates payroll in circumstances that require PAYE registration. A director who pays themselves a salary through the company may also need to consider employer registration and payroll obligations, depending on the circumstances.

You will use the references when managing PAYE, accessing the relevant HMRC services and making employer payments. HMRC provides these details as part of the employer registration process. Do not confuse an employer PAYE reference with the company's Corporation Tax UTR. They identify different tax arrangements.

9. EORI Number for Importing and Exporting

An Economic Operators Registration and Identification (EORI) number is used for relevant customs activities. Not every UK company needs one. Whether you require an EORI number depends on your import and export activities and the customs procedures involved.For many businesses importing goods into or exporting goods from Great Britain, a GB EORI number may be necessary. Separate requirements can apply to certain movements involving Northern Ireland and the European Union.

You must apply for the appropriate number rather than expecting it to arrive automatically when the company is incorporated. A GB EORI application may require information such as the company's UTR, business start date and SIC code. If your company only provides digital services and does not undertake relevant customs activities, you may not need an EORI number at all.

10. Registered Email Address and Government Gateway Details

Not every important company identifier is a number.

Registered email address

When incorporating a company, you must provide a registered email address for official Companies House communications. This address is not displayed publicly on the company register, but it must be kept up to date. Use an email address that the company can reliably access, even if the founder or director is overseas.

Government Gateway user ID

You will need the appropriate HMRC online account access to manage the company's tax services. The standard company registration process requires a Government Gateway user ID for the company; your personal Government Gateway ID should not be used as a substitute for the company's account. Keep the account credentials secure and make sure the relevant director or authorised adviser can access the necessary services.

Quick Reference: Which Numbers and Codes Will Your Company Receive?

Frequently Asked Questions

1. What is the first number a UK company receives?

The first key identifier is the Company Registration Number (CRN), issued by Companies House when the company is incorporated. It appears on the certificate of incorporation.

2. Does a new UK company automatically receive a UTR?

A company registered through the standard Companies House process will usually be set up for Corporation Tax at the same time, unless it is dormant. HMRC generally sends the 10-digit UTR separately, so it may not arrive with the incorporation documents.

3. Is the company number the same as the UTR?

No. Companies House issues the CRN to identify the legal entity on the company register. HMRC uses the UTR to identify the company for Corporation Tax purposes.

4. Does every new company need a VAT number?

No. A VAT number is issued after successful VAT registration. Whether registration is compulsory depends on the business's circumstances and applicable VAT rules, although eligible businesses can register voluntarily.

5. Where can I find my Companies House authentication code?

If you do not have it, you can request it through the relevant Companies House online service. It is normally sent by post to the registered office and can take up to 10 working days to arrive.

6. What is the difference between a SIC code and a company number?

The company number uniquely identifies the registered company. A SIC code describes its business activity and is selected from the applicable classification system.

7. Will I receive a PAYE reference if I do not employ anyone?

Not necessarily. PAYE and Accounts Office references are associated with employer registration. A company that does not need to operate PAYE will not automatically receive them simply because it has been incorporated.

8. Can a non-UK resident obtain these numbers for a UK company?

Yes. A non-UK resident can establish a UK company if the applicable requirements are met. The company will receive its CRN upon incorporation, while tax references and other codes depend on the relevant registrations. Overseas founders should plan for postal delivery, identity verification and access to official company correspondence.

Conclusion

A newly incorporated UK company does not receive every possible business number or code at once. The Company Registration Number is issued at incorporation, while the Corporation Tax UTR usually follows through HMRC's registration process. Authentication codes, personal codes, VAT numbers, PAYE references and EORI numbers serve different purposes and become relevant at different stages.

The practical next step is to create a secure company records folder containing your certificate of incorporation, CRN, UTR, authentication code, identity-verification details and any additional tax or customs references that apply. For founders managing a UK business from abroad, keeping these identifiers organised is particularly important. A reliable company management process whether handled internally, with an accountant or through a platform such as IncorpUK, can help you keep official correspondence accessible, understand which registrations are still outstanding and avoid confusing one identifier with another.