One of the most common questions new business owners in the UK ask is whether they need to register with Companies House as a sole trader. The short answer is no. But the full picture involves understanding which registrations you actually need, what reference numbers you receive, and what obligations sit on your shoulders from day one. This guide breaks it all down.
Key Takeaways
Sole traders in the UK do not register with Companies House. Companies House is the official government agency responsible for registering limited companies, limited liability partnerships, and other incorporated structures. If you run a sole trader business, your registration is with HMRC for self assessment, not Companies House.
Sole traders do not receive a company registration number (CRN). Instead, HMRC issues a unique taxpayer reference (UTR), a 10-digit number used for tax identification purposes and for filing your annual self assessment tax return.
As a sole trader, you must keep accurate records of all income and expenses, pay income tax on your profits, and pay national insurance contributions (Class 2 and Class 4), all calculated through the self assessment system.
Some sole traders later choose to form a limited company and register with Companies House. This can provide name protection, limited liability, and certain advantages around tax efficiency as the business grows.
From 6 April 2026, making tax digital for Income Tax applies to sole traders and landlords with qualifying income over £50,000, increasing the need for digital records and quarterly reporting to HMRC.
What Is Companies House and How Does It Relate to Sole Traders?
Before diving into the registration process, it helps to understand what Companies House actually does and why it matters (or doesn't) for sole traders.
Companies House is the UK's official registrar of companies. It maintains the public register of incorporated entities, including:
Private limited companies (Ltd)
Public limited companies (PLC)
Limited liability partnerships (LLPs)
Companies limited by guarantee
Companies House allows public access to company information for registered businesses. When a business incorporates, it receives a company registration number (CRN) that stays with it permanently, even if it changes name or address. This is the identifier used on invoices, a business website, and official correspondence.
Here is the key point: sole traders are not registered with Companies House because they are not a separate legal entity from their owners. The individual and the business are the same entity. There is no incorporation, no share capital, and no CRN.
Most sole traders will never need to deal directly with Companies House unless they decide to form a limited company in the future. Their entire compliance relationship sits with HM Revenue & Customs.
Do Sole Traders Register With Companies House?
To put it plainly: as of the 2026/27 tax year, UK sole traders do not and cannot register their sole trader business with Companies House.
When someone operates under the sole trader business structure, the individual and the business are legally the same person. There is no legal separation between the two. Being a sole trader means you are personally responsible for every aspect of the business, from contracts to debts to taxes. No separate company record is created at Companies House.
This is fundamentally different from limited companies, where incorporation with Companies House is compulsory. When a limited company forms, it receives a company name on the public register and a CRN. That company becomes a separate legal entity with its own rights and obligations.
If you see advice telling you to "register a sole trader with Companies House," it almost always means forming a limited company, not registering sole trader status itself.
Sole traders can still trade under a chosen business name. But that trading name is not "registered" at Companies House. It does not appear on any public register, and it grants no exclusive rights over the name. Sole traders retain full control of their business, and their details are not publicly listed in the way that company director information is.
Financial information of sole traders remains private and is not disclosed publicly. This is a notable difference from limited companies, where annual accounts are filed and accessible to anyone.
What Numbers Do Sole Traders Get Instead of a Company Number?
Sole traders deal mainly with HMRC references rather than Companies House identifiers. Here is what you receive and what you do not.
When you register as a self employed person with HMRC, you are issued a unique taxpayer reference UTR. A UTR is a 10-digit number assigned by HMRC. Sole traders receive their UTR after registering with HMRC. It can take up to 15 days to receive a UTR from HMRC, delivered by post (longer if you are overseas).
The UTR is used for tax identification purposes. You use it to:
File your self assessment tax return each year
Pay income tax and national insurance contributions
Communicate with HMRC about your tax obligations
Your UTR stays the same throughout your life, even if you stop trading for a period and restart later. If you also set up a limited company, that company receives its own separate UTR for corporation tax purposes.
A company registration number (CRN) only exists where there is a Companies House-registered company. Sole traders do not receive a company registration number.
Privacy matters. Sole traders must keep their UTR confidential to prevent fraud. The UTR should only be shared with HMRC, your accountant, or your bank when specifically requested. CRNs, by contrast, are public and designed to be displayed on invoices, websites, and company stationery.
Identifier | Issued By | Who Gets It | Public or Private |
|---|---|---|---|
Company Registration Number (CRN) | Companies House | Limited companies, LLPs | Public |
Unique Taxpayer Reference (UTR) | HMRC | Sole traders, companies (separate UTRs) | Private |
National Insurance Number | HMRC/DWP | All UK workers | Private |
How to Register as a Sole Trader (Step by Step)
This section walks through the current UK process for registering as a sole trader with HMRC, not Companies House.
You must register for self assessment if you earn over £1,000 in gross self employment income during a tax year (running 6 April to 5 April). Sole traders must register with HMRC for self-assessment. Here are the key steps:
Obtain or confirm your national insurance number. You need this before you can register. If you do not have one, apply through the relevant government service.
Create or sign in to a government gateway account. This is the online portal HMRC uses for tax services.
Complete the online "Register for Self Assessment" form. You will indicate that you are registering as self employed. Provide your personal details, trading name (if any), and the date you started trading.
Wait for your UTR. It takes up to 15 days to receive a unique taxpayer reference. HMRC sends it by post.
You must register for Self Assessment by 5 October in your business's second tax year. For example, if you start trading during the 2026/27 tax year (which runs 6 April 2026 to 5 April 2027), you must notify HMRC by 5 October 2027. Missing this deadline can trigger late registration penalties.
Once registered, you file an annual tax return online each year. Sole traders must file an annual tax return with HMRC. The deadline for online filing is 31 January following the end of the tax year. Any income tax and national insurance due must be paid by the same date (with possible payments on account required earlier).
Tax, National Insurance, and Making Tax Digital for Sole Traders
Understanding what you actually pay tax on and how reporting is changing is essential for every self employed person.
What sole traders pay
Sole traders pay income tax on their profits, calculated as total income minus allowable expenses. They also pay national insurance contributions:
Class 2 NIC - a flat-rate contribution that helps build entitlement to the state pension and certain benefits.
Class 4 NIC - calculated as a percentage of profits above an annual threshold.
Sole traders must pay Class 2 and Class 4 National Insurance contributions. Thresholds and rates change annually in UK Budgets, so check the latest figures each tax year.
Sole traders do not pay corporation tax. Corporation tax applies only to limited companies on their business profits.
All of these obligations are calculated from the annual self assessment tax return. How much you pay depends on your total personal income, including any employment income taxed under PAYE.
Making Tax Digital (MTD)
From 6 April 2026, making tax digital for Income Tax Self Assessment applies to sole traders and landlords with qualifying income over £50,000. "Qualifying income" means gross self-employment income plus gross UK property income, before deducting expenses. Employment income under PAYE does not count.
The thresholds are being phased down:
Tax Year | Qualifying Income Threshold |
|---|---|
2026/27 | £50,000 |
2027/28 | £30,000 |
2028/29 | £20,000 |
Those in scope must keep digital records using HMRC-recognised software and send quarterly updates summarising income and expenses, followed by a final declaration at year end.
Quarterly deadlines for the 2026/27 tax year are:
Q1: 7 August 2026
Q2: 7 November 2026
Q3: 7 February 2027
Q4: 7 May 2027
Final Declaration: 31 January 2028
HMRC has announced a "soft landing" for the first 12 months: those joining MTD from April 2026 will not receive penalty points for late quarterly updates during this initial period. However, late payment penalties still apply.
Using compatible accounting software or apps is the simplest way to maintain accurate records and simplify both your annual assessment tax return and future MTD submissions.
Choosing and Protecting a Sole Trader Business Name
The rules around naming differ significantly for sole traders and limited companies. Companies House only protects limited company names on its register.
Sole traders can trade under their own name or a business name. Sole traders can operate under their own name or choose a trading name registered with HMRC. For example, "Sarah Clarke" could trade as "Clarke Consulting." However, you must not suggest you are a limited company by using "Limited," "Ltd," or "PLC" in your trading name. That would be misleading and potentially unlawful.
Before settling on a business name, take these steps:
Search Companies House for any existing company name that matches or closely resembles your chosen name.
Search the UK Intellectual Property Office (UKIPO) trademark register for conflicting trademarks.
Check domain availability so you can secure a matching web address.
Using a business name as a sole trader does not stop someone else from incorporating a limited company with the same or similar name at Companies House. Your trading name has no legal protection through Companies House alone.
To reinforce your brand and build some informal protection:
Register a domain matching the business name
Set up a professional business website and email
Consider trademark registration with the UKIPO for stronger, legally enforceable protection
Use consistent branding across all platforms and invoices
Record-Keeping and Compliance Obligations for Sole Traders
Despite not filing anything with Companies House, sole traders have real compliance obligations. Getting them right protects your business finances and keeps HMRC satisfied.
HMRC expects sole traders to keep complete and accurate records of all business income and expenses. Sole traders must maintain accurate records of all business income and expenses. This includes:
Sales invoices and receipts
Purchase invoices and receipts
Bank statements for any business bank account
Mileage logs, if applicable
Records of any other taxes paid
Sole traders must keep financial records for at least 5 years after the 31 January filing deadline for the relevant tax year. If HMRC opens an enquiry, you may need to retain records for longer.
Good bookkeeping underpins accurate self assessment tax returns, supports allowable expense claims, and prepares you for any HMRC enquiry. Separating your personal finances from your business finances using a dedicated business bank account is strongly recommended, even though it is not a legal requirement for sole traders.
With making tax digital rolling out, moving to a digital record-keeping system now makes sense. Software that can produce reports and export data will make quarterly updates straightforward when HMRC requires them.
Other registrations to watch
As your business grows, other responsibilities may arise:
VAT registration - required when turnover exceeds the current VAT threshold. Even vat registered businesses that are sole traders remain sole traders; VAT is a separate obligation.
PAYE - if you start employing staff, you need to register as an employer and operate PAYE.
When Would a Sole Trader Use Companies House?
While sole traders do not register with Companies House, there are specific scenarios where they might interact with it.
Forming a limited company
The most common route is converting an established sole trader business into a limited company structure. This means you register with Companies House, obtain a company name and CRN, and the new company becomes a separate legal entity. You then operate through the company rather than as a sole trader.
Protecting a business name
Some sole traders form a dormant limited company purely to protect a preferred company name from being registered by someone else. The dormant company sits on the register, holding the name, with minimal paperwork required (just confirmation statements and dormant company accounts).
What changes on incorporation
Forming a limited company changes the business structure significantly. The company must pay corporation tax on profits, file annual accounts with Companies House, submit confirmation statements, and meet separate director and shareholder responsibilities. The company also needs its own business bank account.
Any switch from sole trading to a limited company should be carefully timed and often coordinated with an accountant so that tax, national insurance, and contracts transition smoothly. Business decisions about structure should factor in the level of personal liability you are comfortable with and whether your business profits justify the additional administration.
Limited Company vs Sole Trader: Key Differences
This section provides a high-level comparison rather than a full guide to incorporation.
Factor | Sole Trader | Limited Company |
|---|---|---|
Legal status | You and the business are the same entity | A separate legal entity from its owners |
Liability | Unlimited - personal assets are at risk if the business incurs debts it cannot pay | Limited liability - shareholders generally risk only the unpaid nominal value of their shares |
Registration | HMRC (Self Assessment) | Companies House + HMRC |
Tax | Income tax on profits via Self Assessment | Corporation tax on company profits |
Public information | Financial records are private | Annual accounts are public via Companies House |
Name protection | None via Companies House | Company name protected on the register |
Admin burden | Minimal paperwork, simpler reporting | More filings, annual accounts, confirmation statements |
A sole trader has unlimited personal liability, meaning personal assets are at risk if the business cannot pay its debts. Sole traders are personally liable for business debts. Limited companies are separate legal entities from their owners. Limited companies offer limited liability protection to owners, generally limiting risk to the unpaid nominal value of shares.
Limited companies often enjoy more credibility with larger clients, lenders, and investors, and may offer tax planning opportunities once profits reach certain levels. The sole trader model, on the other hand, suits many freelancers and small, early-stage businesses where simplicity, lower costs, and straightforward self assessment outweigh the financial protection of incorporation.
The right business structure depends on your risk profile, income level, and long-term plans. Neither option is universally "better."
FAQ
Does a sole trader ever get a Companies House company registration number?
No. A pure sole trader business never receives a Companies House company registration number. A CRN is only issued when a separate limited company (or LLP) is formed and registered with Companies House. If you operate solely as a sole trader, your identifier for tax purposes is your unique taxpayer reference from HMRC, not a CRN.
Can I appear “more professional” without forming a limited company?
Absolutely. Many successful sole traders build strong professional brands without incorporating. Practical steps include choosing a consistent business name, registering a matching domain, launching a simple and credible business website, and using professional email addresses and invoices. These signal professionalism to clients without requiring Companies House registration or the administrative overhead of running your own business as a limited company.
Can I be employed and a sole trader at the same time?
Yes. You can hold a regular job under PAYE while running a sole trader business on the side. Your employment income is taxed by your employer through PAYE, and your business profits are reported separately on your self assessment tax return. You still need to register as a sole trader with HMRC if your self employment income exceeds £1,000.
Will Companies House contact me if I am only a sole trader?
Companies House does not usually contact individuals solely because they are sole traders. Official letters about filings, CRNs, or compliance deadlines only apply to businesses that have incorporated a company or formed an LLP. If you receive correspondence from Companies House and have not incorporated anything, it may be a scam or sent in error.
How do I switch from sole trader to limited company later?
The basic steps are:
Choose a company name and check availability on the Companies House register.
Register the limited company with Companies House (online or via a formation agent).
Open a business bank account in the company's name.
Update HMRC about the new business structure, registering for corporation tax and, if needed, PAYE.
Gradually move contracts, assets, and invoicing from the sole trader to the company.
Notify HMRC that you have ceased self employment if you are no longer trading as a sole trader.
Coordinating the timing with an accountant ensures that your tax year, national insurance, and existing contracts transition without gaps or double reporting.
