How to Start a Small Business in the UK: Legal Structures, HMRC Registration, and Taxes

Starting a small business is the formal process of establishing a commercial enterprise by selecting a legal structure, registering with official bodies like HMRC or Companies House, and complying with UK tax and regulatory duties.

As of the 2026/27 tax year, this framework supports over five million active small businesses nationwide.

Key Takeaways

• The £1,000 trading allowance lets a sole trader earn that much tax-free before HMRC registration becomes compulsory.
• VAT registration becomes mandatory once taxable turnover passes £90,000 in any rolling 12-month period.
• Running a small business from home is legal, though it can trigger business rates and insurance requirements.

How to Start a Small Business?

Moving from an initial concept to an active trading enterprise involves a structured sequence of practical steps. While every sector has unique demands, the core roadmap remains consistent across the UK:

1. Validate the business idea: Test demand, research competitors, and confirm there is a viable paying customer base before spending capital.

2. Choose a business structure: Decide between operating as a sole trader or setting up a limited company based on liability, tax efficiency, and growth plans.

3. Handle official registration: Register with HMRC (for sole traders) or incorporate through Companies House (for limited companies).

4. Open a business bank account: Separate personal and business finances to simplify tax returns and build financial credibility.

5. Secure necessary insurance: Protect the business with public liability, professional indemnity, or employers’ liability cover depending on operational risks.

6. Set up tax and record-keeping systems: Keep clear records of all income and expenses, and familiarise yourself with filing deadlines for Self Assessment or Corporation Tax.

Which Business Structure Should You Choose, Sole Trader or Limited Company?

Most UK small businesses register as either a sole trader or a limited company, and the choice affects tax, paperwork, and personal financial risk.

Factor	Sole trader	Limited company
Liability	Personal, unlimited	Limited to shares owned
Setup	Register for Self Assessment	Register with Companies House
Tax	Income Tax + National Insurance	Corporation Tax + tax on salary/dividends
Paperwork	One Self Assessment return	Annual accounts + Companies House filing
Best for	Solo, lower-risk ventures	Growth-focused or higher-liability work

A partnership sits between the two, splitting profits and liability between two or more people, but it’s far less common than either main option.

Businesses planning to raise investment or bring in shareholders generally outgrow sole trader status quickly, since only a limited company can issue shares.

A specialist accountant can advise on borderline cases, particularly where regulated activities are involved, some accountants must themselves be authorised by the Financial Conduct Authority (FCA) to offer certain services.

How to Register Your Business With HMRC or Companies House?

Registering a sole trader business means signing up for Self Assessment with HM Revenue and Customs (HMRC); registering a limited company means incorporating with Companies House first.

1. Decide a trading name and check it isn’t already registered at Companies House.
2. Sole traders: register for Self Assessment by 5 October following the tax year in which self-employment income exceeds £1,000.
3. Limited companies: register with Companies House online for a standard £50 fee.
4. Note the Unique Taxpayer Reference (UTR) HMRC issues on registration; it’s needed for every future tax return.
5. Open a dedicated business bank account, mandatory for limited companies, strongly advisable for sole traders.

This process involves identity and anti-money laundering checks (KYC), which can take anywhere from a few days to a couple of weeks depending on the provider.

Limited companies carry an extra ongoing duty sole traders don’t: filing a confirmation statement with Companies House at least once a year, confirming the company’s details are still accurate. Missing this deadline can lead to the company being struck off.

Can You Legally Run a Small Business From Home?

Yes, running a small business from home is legal in the UK, though it can trigger business rates, insurance changes, and tenancy or mortgage checks depending on how the space is used. Small business rate relief usually applies where the property’s rateable value is below £15,000.

A recurring question raised with tax advisers involves exactly this situation: a sole trader running a craft business from a dedicated room at home, alongside full-time employment elsewhere.

The guidance given was consistent, register as self-employed with HMRC regardless of the day job, and keep records of materials, equipment, and a proportion of utility costs tied to that dedicated space, since these can usually be claimed as business expenses.

The same exchange raised a common point of confusion worth settling here: the £1,000 trading allowance applies to self-employment income specifically, not combined with earnings from a separate job.

What Will It Actually Cost to Start a Small Business?

Setting up a small business in the UK can cost as little as £50 in registration fees, though realistic budgets for equipment, insurance, and marketing typically reach the low thousands.

Costs generally fall into specific categories:

• Registration and legal fees

• Equipment or stock

• Websites or digital listings

• Insurance and marketing spend

• Premises (if required), which typically forms the largest single expense.

Low-cost ways to start

• Work from home rather than renting premises.
• Use free or low-cost tools before paying for software.
• Buy used equipment where quality allows it.
• Test the idea with a small batch before committing to bulk stock.

Can You Start a Small Business With No Money?

Yes, starting a small business with no money is possible in the UK, particularly for service-based businesses needing no stock or premises.

A government-backed Start Up Loan can provide £500 to £25,000 with fixed interest, alongside free mentoring, a realistic middle ground between self-funding and a traditional bank loan.

Funding options if more is needed

1. Self-funding from savings, where affordable.
2. A government-backed Start Up Loan of £500 to £25,000.
3. Small business grants, which, unlike loans, don’t need to be repaid.
4. Crowdfunding, for ideas with genuine public appeal.
5. Bank loans or alternative lenders, usually requiring a business plan and financial history; rates tend to track the Bank of England base rate, so comparing offers is worthwhile.

How Much Tax Will a Small Business Owner Pay?

Tax obligations depend on structure: sole traders pay Income Tax and National Insurance through Self Assessment, while limited companies pay Corporation Tax on profits, plus separate tax on any salary or dividends the owner draws from the company.

Corporation Tax is charged at different rates depending on profit level, so a limited company’s total tax bill isn’t simply a fixed percentage; an accountant can confirm which rate applies to a specific profit figure.

VAT registration becomes mandatory once taxable turnover passes £90,000 in a rolling 12-month period, though voluntary registration is possible earlier.

Making Tax Digital for Income Tax is being phased in for the self-employed: qualifying income over £50,000 from April 2026, over £30,000 from April 2027, and over £20,000 from April 2028.

Sole traders and partners with combined turnover under £150,000 can also use simplified cash-basis accounting rather than traditional accruals.

What Insurance and Legal Protections Are Needed?

The right business insurance depends on what the business does, but public liability and professional indemnity cover are the two most commonly needed.

• Public liability insurance: covers claims from members of the public.
• Professional indemnity insurance: covers claims arising from negligent advice or service.
• Employers’ liability insurance: a legal requirement once staff are hired.
• Equipment or premises insurance: covers tools, stock, and business property.

None of these are usually legally required for a sole trader working alone from home, with the exception of employers’ liability insurance the moment anyone is hired.

Even so, many clients, landlords, and lenders expect to see proof of at least public liability cover before agreeing to work together.

Disputes over financial products, including some insurance claims, can be escalated to the Financial Ombudsman Service if a provider won’t resolve them directly.

Conclusion

Starting a small business in the UK comes down to a handful of concrete steps: validate the idea, choose a structure, register correctly, and understand the tax and insurance obligations that follow.

Launching a venture does not require large capital or specialist knowledge from day one; most necessary resources are available directly through GOV.UK, MoneyHelper, and HMRC.

Disclaimer: Tax rates, thresholds, and registration fees change with each tax year and Budget announcement. Figures in this article reflect rates published as of September 2026; readers should confirm current details directly with HMRC or GOV.UK before acting.

FAQs

How do you start a small business with no money?

Many UK small businesses start for under £100 by working from home and avoiding premises costs. A government-backed Start Up Loan of £500 to £25,000 is also available. Service-based businesses needing no stock are typically the cheapest to launch.

Can you run a small business from home in the UK?

Yes, running a small business from home is legal. Depending on how the space is used, it may trigger business rates, a tenancy or mortgage check, and adjusted home insurance.

What’s the easiest business structure for a first-time small business owner?

Sole trader status is usually the simplest structure, requiring only Self Assessment registration with HMRC. It suits low-risk, single-owner ventures, though it carries personal liability for business debts.

Do you need to register as self-employed straight away?

No, registration is only required once self-employment income exceeds £1,000 in a tax year. Below that threshold, covered by the trading allowance, no registration or tax return is necessary.