Choosing a Business Structure in the UK: Sole Trader, Partnership, LLP or Ltd?

Why the Choice of Structure Matters

Every new UK business must choose a legal structure. This is not just a formality -- the structure determines how you are taxed, how much personal liability you carry, how you are regulated, and how much administrative burden you face. The wrong choice at the outset can cost thousands in unnecessary tax or leave you personally exposed to business debts.

The four principal structures for UK businesses are:

1. Sole trader
2. General partnership
3. Limited Liability Partnership (LLP)
4. Private limited company (Ltd)

This guide explains how each works, how each is taxed, and the practical considerations for choosing between them.

Sole Trader

What It Is

A sole trader is simply an individual operating a business in their own name. There is no separate legal entity -- you and the business are one and the same. This is the most common structure for freelancers, tradespeople, and small businesses.

Tax Treatment

Sole traders pay income tax on their trading profits at the standard income tax rates:

• 20% basic rate on profits between GBP12,570 and GBP50,270
• 40% higher rate on profits between GBP50,271 and GBP125,140
• 45% additional rate on profits above GBP125,140

In addition, sole traders pay Class 4 National Insurance Contributions:

• 6% on profits between GBP12,570 and GBP50,270
• 2% on profits above GBP50,270

And Class 2 NIC of GBP3.45 per week (though from 2024 Class 2 is treated as optional for those with profits above the Small Profits Threshold, with Class 2 still counting toward state benefits entitlement).

Example: Sole trader with GBP50,000 profit:

• Income tax: approximately GBP7,540 (basic rate, after Personal Allowance)
• Class 4 NI: approximately GBP2,256
• Total tax and NI: approximately GBP9,796

Administration

Sole traders register with HMRC as self-employed (must do so within three months of starting), file a Self Assessment tax return each January, and pay tax twice a year (January and July). No company accounts, no Companies House filing, no audit requirements.

Liability

There is no limit on personal liability. If the business has debts, creditors can pursue the owner's personal assets -- home, savings, investments.

When to Use

Sole trading suits low-to-medium profit businesses where the simplicity and low cost outweigh any tax disadvantage. For businesses with profits under GBP30,000, the sole trader structure is often perfectly efficient. For higher profits, the tax bill climbs quickly.

General Partnership

What It Is

A general partnership is formed when two or more people run a business together without forming a separate legal entity. No formal agreement is required, though a partnership agreement is strongly recommended.

Tax Treatment

Each partner pays income tax on their share of the partnership's profits at their own marginal rates. Partners are self-employed individuals for tax purposes, filing Self Assessment returns and paying Class 4 NI on their share of profits.

The partnership itself files a Partnership Tax Return (SA800) showing total income and each partner's allocation -- but the partnership does not pay tax. Tax is paid by each individual partner.

Liability

In a general partnership, every partner has unlimited joint and several liability for the debts and obligations of the partnership. If one partner makes a mistake that results in a large claim, all partners are personally liable -- including for the negligent partner's share.

Administration

Relatively simple. Annual partnership return plus individual Self Assessment returns. No Companies House filing.

When to Use

General partnerships are common for small businesses with multiple owners, family businesses, and professions. They are increasingly rare for anything other than simple arrangements because the unlimited liability is a significant deterrent. LLPs offer the same income tax treatment with limited liability.

Limited Liability Partnership (LLP)

What It Is

An LLP is a hybrid structure -- it has the tax transparency of a partnership (partners pay income tax on their share of profits) but provides limited liability similar to a company. LLPs must be registered at Companies House and must file annual accounts (though small LLPs have reduced disclosure requirements).

LLPs must have at least two members (either individuals or corporate members). Members' profit-sharing arrangements are set out in an LLP agreement.

Tax Treatment

The LLP itself does not pay tax. Each member pays income tax and NI on their allocated profit share at their personal marginal rates -- exactly as in a general partnership. Members are treated as self-employed (not employees) for tax purposes, though there are "salaried member" rules (introduced in 2014) that treat members who have disguised employment arrangements as employees subject to PAYE and NI.

The salaried member rules apply where a member:

• Has a variable profit share that depends predominantly on the firm's results (not met if the member has a fixed salary-like share regardless of profits)
• Has significant influence over LLP affairs (not met if the member is a junior participant)
• Has no meaningful financial interest in the LLP (not met if the member has capital at risk)

Professional firms must review whether any of their members fall within the salaried member rules -- HMRC has actively applied these rules since 2014.

Administration

LLPs must register at Companies House, file annual accounts (with reduced disclosure for small LLPs), file a Confirmation Statement, and maintain statutory records. Members file individual Self Assessment returns.

When to Use

LLPs are the structure of choice for:

• Professional services firms (law, accountancy, architecture, consulting)
• Property investment partnerships where partners want limited liability
• Any partnership where the members want income tax treatment but protection from personal liability

They are particularly useful for regulated professions that cannot use the limited company structure, or where income tax pass-through is preferable to the corporation tax/dividend extraction route.

Private Limited Company

What It Is

A private limited company (Ltd) is a separate legal entity from its shareholders and directors. It can own assets, enter contracts, and incur liabilities in its own name. Shareholders' liability is limited to the amount they have paid (or agreed to pay) for their shares.

Companies must be registered at Companies House, file annual accounts, file a Confirmation Statement, and pay corporation tax.

Tax Treatment

Companies pay corporation tax on their profits:

• 19% on augmented profits up to GBP50,000
• 25% on augmented profits above GBP250,000
• Marginal relief (effective rate approximately 26.5%) on profits between GBP50,000 and GBP250,000

After corporation tax, remaining profits can be distributed to shareholders as dividends. Shareholders pay income tax on dividends at:

• 8.75% (basic rate, after the GBP500 dividend allowance)
• 33.75% (higher rate)
• 39.35% (additional rate)

A director-shareholder typically takes a small salary (up to the NI secondary threshold, GBP5,000 in 2026/27 for employer contributions) or the personal allowance level, and extracts the rest as dividends. This reduces NI exposure while maintaining some NI credit for State Pension purposes.

Example: Director with GBP50,000 company profit

Salary of GBP12,570 (within Personal Allowance, no income tax; Class 1 NI is payable but kept minimal):

• Company profits after salary: approximately GBP37,430
• Corporation tax at 19%: GBP7,112
• Remaining distributable profit: GBP30,318
• Dividend (basic rate): GBP30,318 x 8.75% = GBP2,653
• Total tax on GBP50,000: approximately GBP9,765 (less than the sole trader equivalent only for certain profile combinations)

The actual tax comparison varies significantly based on salary choices, other income, pension contributions, and the total corporation tax rate applying.

Administration

Companies must file annual accounts with Companies House (publicly visible), a Confirmation Statement, a Corporation Tax return (CT600) with HMRC, and run a PAYE payroll for director salaries. Directors have legal duties under the Companies Act 2006. Accountancy fees are typically higher than for sole traders.

When to Use

A limited company is most beneficial when:

• Profits are consistently above GBP30,000 to GBP40,000 per year
• The business retains profits rather than distributing all of them immediately
• The business will eventually be sold (share sales qualify for BADR at 18% CGT)
• The business carries significant contract or liability risk

Comparison Summary

Making the Decision

Profit Level

Below GBP30,000: Sole trader is probably sufficient. The administration cost of a company (accountancy fees, Companies House filings) can exceed any tax saving.

GBP30,000 to GBP50,000: The comparison is closer. It depends on how much of the profit you need to extract versus retain.

Above GBP50,000: A limited company generally offers a tax advantage through the corporation tax rate, dividend extraction, and the ability to time distributions.

Liability

If your business could face significant claims -- from clients, employees, or the public -- limited liability matters. Both LLPs and limited companies provide this. Sole traders and general partnerships do not.

Future Sale

If you hope to sell the business in future, a limited company provides the cleanest structure for a share sale and BADR eligibility. Goodwill in a sole trader business can also qualify for BADR, but share sales are structurally simpler.

Investors and Growth

If you intend to take on external investment, issue shares to employees, or bring in multiple stakeholders, a limited company is almost always required. LLPs can accommodate multiple members but are less suitable for equity investment structures.

Changing Structure Later

Changing from sole trader to limited company (incorporating) is common and can be done at any time. However, it triggers consideration of goodwill valuation, capital allowances, and the related party restriction on goodwill amortisation described elsewhere.

Changing from a partnership to an LLP is relatively straightforward. Converting from a company to a sole trader or partnership involves a formal winding-up process and has tax consequences.

Conclusion

The choice of business structure is one of the most consequential decisions a new UK business makes. For simplicity and low-level income, a sole trader is hard to beat. For higher profits, limited liability, and long-term tax planning, a limited company provides significant advantages. For professional partnerships requiring limited liability with income tax pass-through, an LLP is typically the right answer.

Take advice from an accountant or tax adviser before making the decision -- especially if profits are above GBP40,000, if the business carries significant liability risk, or if a future sale is on the horizon.