Business Law & Compliance

What Is A Company Registration Number?

Luisa Ddakis | 17 October 2022 | 2 years ago

What Is A Company Registration Number

A company registration number is a unique identifier assigned to a business by Companies House that identifies the company and its legal status. The number is used for various administrative purposes, such as filing annual returns and maintaining company records, and consists of a series of digits, usually seven or eight in length with the first two or three digits usually identifying the country that the business is registered in.

Read on for a more in-depth explanation of company registration numbers, including how to find yours, what it is used for, and how to set one up.

Do All Companies Need A Registration Number?

Before a limited company business can operate in the United Kingdom, it must first register with Companies House. This is the government body responsible for incorporating and dissolving limited companies and maintaining statutory records of company ownership and directors. Companies House also issues certificates of good standing, which are required for businesses to tender for public sector contracts.

Whether your business needs a registration number or not will depend on the company formation type you choose. Sole traders and the self-employed do not need to register their business with Companies House as they are legally the same entity, but they will have other types of unique identifiers, such as a Unique Taxpayer Reference (UTR). This is used to pay income tax and National Insurance on their earnings after completing a Self Assessment Tax Return.

All other types of companies in England and Wales must be registered with Companies House. This includes private limited companies, public limited companies, limited liability partnerships, and other types of businesses regardless of business size and turnover, including those who want to publicly list shares and register for VAT are required to register their business in the UK.

How To Register

If you want to set up a company in the United Kingdom, you will need to obtain a company registration number from Companies House. Companies House also maintains a public register of all companies, which can be searched by the company name or number.

This is a simple process that can be completed online within 24 hours of registering for a fee of £12 per company. Once you have your registration number, you will be able to commence trading but must also register for Corporation Tax within 3 months of starting to do business.

Click here to understand how to register a limited company

Documents & Information That You Will Need To Register

  • Government Gateway user ID and password
  • At least 3 pieces of information about each shareholder and the person registering the business. Choose from; the town of birth, mother’s maiden name, father’s first name, telephone number, national insurance number, and passport number.
Once a company is registered, it will be assigned a unique company number and this number must be used on all official documents, such as annual reports and accounts.

Other Ways To Register

As well as registering a limited company online, there are also options to do this by post, via a company formation agent or company secretarial agents, or using third-party software

if you have t registered for an online filing account.

If you DON’T want the word ‘Limited’ in your business name, then you will need to register by post using form IN01. Postal applications take 8 to 10 days and cost £40 (paid by cheque made out to ‘Companies House’).

Limited Company Business Structure Overview

Limited Company Business Structure Overview

There are four types of business structures that need to register with Companies House: private companies limited by shares, private companies limited by guarantee, public limited companies, and unlimited companies.

Each type of company has different requirements for registration, so it is important to check the relevant legislation before applying, and a brief overview of each structure is included below.

What Are Private Companies Limited By Shares?

A private company limited by shares is the most common type of business entity in the United Kingdom. This type of company is ‘limited’ because it has shareholders who have limited liability for the debts of the company. The shares are issued to raise capital for the company and can be traded on a stock exchange or sold privately.

What Are Private Companies Limited By Guarantee?

A private company limited by guarantee is a type of company often used by charities, clubs, and associations. The members of the company agree to pay a fixed amount (the ‘guarantee’) if the company is wound up.

What Are Public Limited Companies?

A public limited company (PLC) can offer shares to the public and is usually quoted on a stock exchange. A PLC must have a minimum share capital of £50,000 and must meet certain other conditions set out in the Companies Act 2006.

What Are Unlimited Companies?

An unlimited company does not have shareholders but may have members who have ‘unlimited liability’. This means that they are liable for the debts of the company if it cannot pay its creditors.

Unlimited companies are relatively rare and are usually only used by businesses that want to avoid the restrictions that apply to other types of companies.

Benefits To Limited Company Structures

Benefits of setting up a limited company, include;

  • Limited liability: shareholders are only liable for the amount of money they have invested in the company. This protects them from being held responsible for the debts of the company if it cannot pay its creditors.
  • Flexibility: a limited company can be set up with different types of share structures to suit the needs of the business.
  • Tax efficiency: a limited company can claim certain tax reliefs and allowances that are not available to other types of business.
  • Status: a limited company may be seen as more professional than a sole trader or partnership.

Drawbacks To Limited Company Structures

Drawbacks to setting up a limited company include;

  • Complexity: a limited company is more complex to set up and run than a sole trader or partnership. There are more legal and financial obligations that need to be met.
  • Cost: a limited company costs more to set up than a sole trader or partnership.
  • Bureaucracy: a limited company is subject to more regulation than a sole trader or partnership. This can be seen as a disadvantage as it can be time-consuming and costly to comply with all the requirements.
If you work with a company formation agent when setting up your business, they will ensure that you choose the right business structure, can assist with the incorporation of the company, and help to register it with HMRC. This ensures that you register the business correctly and obtain the necessary licenses and permits for your area of work and can be a great professional help in the set up of a new company.

How Are Company Registration Numbers Used?

How are company registration numbers used

This number is assigned by the Companies House when you register your company. You can register your company online or through a company formation agent. Once you have registered your company, you will be able to access your company’s public record.

Companies House is a government agency that is responsible for maintaining records of all registered companies. The records include information on the directors and shareholders of the company, as well as the company’s financial statements and registered address. Properly registering your business in this way will allow you to legally operate your business and provide potential investors and HMRC with information about your company.

The number is often used by banks and other financial institutions when opening a business account or extending credit and must be included on your business stationery such as letterheads. It is also used by HMRC when filing your company’s annual return.

When you register your company, you will be given a certificate of incorporation. This document will contain the company registration number as well as other important information about your company. It is advisable to keep this document in a safe place as it may be required for future reference.

Do I Need To Update My Registration?

Companies must file annual returns with Companies House to keep their registration up to date. Failure to do so can result in significant penalties so it is essential for all businesses operating in the UK to ensure that they are properly updating their registration documents.

You should update your company record in the following circumstances:

  • Changing the name of your company or limited liability partnership
  • Changing your registered office address or SAIL address
  • Appointing and removing a company secretary
  • Appointing and removing limited liability partnership members
  • Changing your accounting reference date (ARD)
  • Filing copies of resolutions
  • Adding or removing a company director
  • Selling shares Issuing dividend vouchers to shareholders
  • Dissolving your company or LLP
  • Changing the trading status of your company from active to dormant

How Can You Find Your Company Registration Number?

Following your registration, you should be able to find your company registration number on the initial documents sent to you when the company was formed. Official correspondence with Companies House, such as letters or emails will also contain this information.

If you can’t find these documents, you can use the public register to search the Companies House’s records by company name to find your company registration number. Your registration number can also be found on various documents, including the company’s articles of association, shareholder certificates, annual returns, VAT Returns, and account filings, plus it is often listed on company websites and marketing materials, including headed paper because limited companies and LLPs are legally required to display their CRN on all forms of official business stationery.

If you are unsure where to find your company’s registration number, you can contact Companies House, the government agency responsible for maintaining records of all businesses in the UK.

Can You Make Changes And Does The Registration Expire?

Your company registration number is assigned to you when you first register your business and is used for official purposes, such as filing annual accounts and complying with tax obligations. It can be changed in certain circumstances but it doesn’t expire until you officially register your business as closed with Companies House.

For example, if you’re changing the name of your business or merging with another company, you’ll need to update your registration number to reflect the new name or structure. In most cases, only the registered office address and director details need to be updated with Companies House; the registration number will be automatically updated.

You can also change your registration number if it’s been compromised in some way – for example, if it’s been made public without your permission. In these cases, you’ll need to contact Companies House (the government agency responsible for issuing registration numbers) and request a new number.

If you need to change your company registration number for any other reason, you can do so by contacting Companies House directly and they will action your request. It’s important to note that changing your company registration number won’t affect any of your existing contracts or agreements but it’s always a good idea to update your registered address and contact details with Companies House so that other businesses and organsations can easily get in touch with you.

Related Questions

What Is Companies House?

Any company registered in the UK must be on the Companies House Register. This is a government database of all limited companies in the UK, and it includes information about each company’s directors, shareholders, and financial history. Companies House is also responsible for issuing share certificates, filing annual reports, and managing the dissolution of companies serving as an insolvency service provider. This means that it deals with bankruptcies and other company-related debts. In short, Companies House it plays a vital role in ensuring that businesses in the UK are run transparently and efficiently.

Where Should Your Registered Office Address Be?

Choosing the right registered office address is an important decision for any business owner. The registered office address is the official address of a company, and it must be displayed on all company documentation, including letterheads and websites. It is also the address that will be used for any legal correspondence.

Many new businesses opt to use their home address as their registered office address, but there are a few things to consider before making this choice. Using a home address can make it difficult to keep business and personal matters separate as your home address will be publicly listed on company documentation. If you have a physical shop, warehouse or office where you run your business, you should use this address but another option is to use the address of your accountant or solicitor (it is important to check that your chosen professional is happy for their address to be used in this way), or a serviced office address.

What Company Details Do I Need To Get A Registration Number?

To register a company, you must provide certain details to Companies House. These include the company name, registered address, contact details of the director and secretary, and a description of the business activity. In addition, you will need to pay a fee to the registrar.

The process of registration can be completed online or by mail. Once the registrar has all the required information, they will assign a unique registration number to your company. This number must be displayed on all official documents and correspondence. It is also generally used as a reference point for customers and suppliers.


A company registration number is a unique identifier issued after the incorporation of a company and it’s registration of a business with Companies House in the UK. This is a simple process that can be completed online within 24 hours and once you have your registration number, you will be able to commence trading, but you must also register for Corporation Tax within 3 months of starting to do business.

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