How to get a company registration number (CRN)

When you set up a limited company in the UK, one of the first official things you’ll receive is your company registration number, or CRN. It might not seem like much at first glance – just another string of digits and letters. But it carries serious weight.

Your CRN is more than just an admin label. It’s your company’s legal identity. It’s what ties your business to Companies House. Without it you won’t be able to open a business bank account, register for taxes or issue invoices in your company’s name.

In this guide, we’ll walk you through exactly what a CRN is, why it matters and how to get one. We’ll also explain why getting a CRN could be a step towards more flexibility, more protection and more control over your business.

What is a company registration number?

A company registration number (CRN) is a unique identifier issued by Companies House when you register a new limited company or LLP (limited liability partnership) in the UK. It’s made up of eight characters – either a mix of letters and numbers or just numbers, depending on where you register.

You’ll find your CRN on your certificate of incorporation, and it will stay the same through the existence of your company, even if you change your company name, shareholders, directors or address. Think of it like your company’s National Insurance number. It’s how government bodies, banks and other businesses know you’re legitimate.

When do you need your company registration number?

Your CRN isn’t just a formality, it’s a legal necessity. Here are a few situations where you’ll need it:

• Opening a business bank account 

Most banks will require your CRN to let you open a business account in your company’s name. This number serves as proof that your company is registered on Companies House and legitimate, giving banks the confidence they need to proceed.

• Registering for business taxes 

Your CRN is essential for registering with HMRC for taxes like Corporation Tax, VAT and PAYE. HMRC uses it to track your tax obligations, filings and payments to make sure your business stays compliant with tax laws.

• Filing your annual accounts

Each year, you’ll need to submit annual accounts and confirmation statements to Companies House. You must include your CRN in these filings to identify your company and keep your records up to date.

• Issuing official documents 

Legally, your CRN must appear on all official company documents including invoices, your company website, emails, and letterheads. This helps identify your business and demonstrates its legal status to clients, suppliers and partners.

How do you get a company registration number?

To get a CRN, you’ll need to register your company with Companies House. That means choosing a company name, deciding on your business structure and submitting the right documentation.

1. Register directly through Companies House

You can go straight to the Companies House website and register your business online for £50. It usually takes 24 hours.

You’ll need to provide:

• A company name that isn’t already taken
• At least one director
• A registered office address in the UK
• Shareholder details and share capital structure
• SIC code (which describes what your business does)

Once accepted, you’ll get your company CRN via email along with its certificate of incorporation.

2. Use a third-party formation service

You can also register your company through a third-party provider. This could be an accountant, business formation agent or even a bank or online platform that bundles company registration with other services like accounting, legal advice or banking.

This is helpful if you want additional support beyond just registering your company. Costs and processing times will vary depending on who you choose so it’s worth comparing a few options to find one that fits your budget and needs.

3. Register your business through Zempler Bank

Zempler Bank offers a simple company formation service built directly into our business banking platform. You can register your limited company and apply for your business bank account at the same time in one smooth digital flow.

Load £100 into your account within the first 30 days and we'll reward you with £100.

No paperwork. No complicated forms. Just a few quick details and we’ll handle the rest. Your company’s CRN and certificate of incorporation will usually land in your inbox within a day.

It’s a simple way to start a limited company if you’re looking for speed, ease and no hidden fees.

Learn more about our Formations service.

Do sole traders get a CRN?

If you’re currently self-employed as a sole trader, you might be wondering if you already have – or need – a CRN. The answer is no.

Here’s the key distinction:

• Sole traders don’t get a CRN because they don’t need to register with Companies House
• Limited companies do get a CRN because they are legally separate from the people who run them and do register with Companies House.

So if you’re a sole trader, you won’t have a CRN. Instead, you’ll register with HMRC for Self-Assessment and operate under your own name or a trading name.

Form your company with Zempler Bank

Starting a business is a big step – we know that as well as anyone (because we’ve done it ourselves). That’s why we’ve made it as simple and seamless as possible to form a company and open a business account at the same time.

With Zempler you can take advantage of:

• Fast registration – get your CRN and certificate of incorporation in as little as 24 hours
• No paperwork – our digital-first process cuts out the admin
• Transparent pricing – no hidden fees or surprise charges
• Business tools from day one – real-time transaction notifications, built-in expense tracking and cash flow insights to name but a few
• UK-based customer support – speak to someone who understands small business life

Whether you’re a freelancer looking to level up or a sole trader thinking about going limited, we’ll help you take the next business step with confidence and clarity.

Learn more about our Formations service.