Sole Trader vs Limited Company: Which Is Better for Tax?

One of the most common questions we hear from self-employed people and small business owners is: “Should I incorporate?” The answer depends on your profit level, personal circumstances, and business goals. In this comprehensive guide, we compare the tax treatment of sole traders and limited companies at multiple profit levels, covering income tax, National Insurance, dividends, and the practical considerations that go beyond pure tax savings.

How Sole Traders Are Taxed

As a sole trader, you and your business are the same legal entity. All business profits are treated as your personal income and taxed through Self Assessment. The key taxes you pay are:

• Income Tax on all profits after deducting allowable business expenses, at the standard rates (20%, 40%, 45%)
• Class 2 National Insurance: £3.45 per week (£179.40 per year) if profits exceed £12,570
• Class 4 National Insurance: 6% on profits between £12,570 and £50,270, plus 2% on profits above £50,270

The main advantage of being a sole trader is simplicity. You file a single Self Assessment return, keep basic records, and there is no requirement for formal accounts to be filed at Companies House. Setup costs are nil — you simply register with HMRC. The main disadvantage is that you have unlimited personal liability for business debts, and the combined income tax and NIC burden can be higher than for an equivalent limited company at higher profit levels.

How Limited Companies Are Taxed

A limited company is a separate legal entity from its owner(s). The company pays Corporation Tax on its profits, and the director/shareholder then extracts money from the company through a combination of salary and dividends. The key taxes are:

• Corporation Tax on company profits: 19% on profits up to £50,000 (small profits rate), 25% on profits over £250,000 (main rate), with marginal relief between £50,000 and £250,000
• Employer's NIC: 13.8% on salary above the Secondary Threshold (£9,100 for 2025/26), but this is a deductible expense for the company
• Employee's NIC: 8% on salary between £12,570 and £50,270 (paid by the director personally)
• Income Tax on dividends: 0% on the first £500 (dividend allowance), then 8.75% (basic rate), 33.75% (higher rate), 39.35% (additional rate)

The typical extraction strategy for a single director/shareholder is to pay yourself a salary equal to the Primary Threshold (£12,570) to preserve State Pension entitlement without triggering NIC, and then take the remaining profits as dividends. This is usually the most tax-efficient approach.

Tax Comparison at Different Profit Levels

Let's compare the total tax burden (including all taxes and NIC) for a sole trader versus a single-director limited company at four profit levels. For the limited company, we assume the optimal salary/dividend split: £12,570 salary plus dividends for the remainder.

Profit Level: £30,000

At £30,000 profit, there is virtually no benefit to incorporating. The sole trader actually takes home slightly more because the limited company route involves Corporation Tax on the full profit before extraction, plus the overhead costs of running a company (accounting fees, filing requirements). The sole trader structure is clearly better at this level.

Profit Level: £50,000

At £50,000 profit, the results are close but the sole trader still edges ahead. The limited company starts to become more competitive here, especially when you factor in the ability to retain profits in the company and the limited liability protection. But on a pure tax-extraction basis, sole trading is still marginally better.

Profit Level: £80,000

At £80,000 profit, the limited company clearly wins. The £1,750 annual saving more than covers the additional accountancy costs of running a limited company (typically £1,000–£2,000 per year). This is often cited as the “crossover point” where incorporation becomes worthwhile.

Profit Level: £120,000

At £120,000, the limited company saves over £6,000 per year. The savings come primarily from the difference between Class 4 NIC rates (6%/2%) and the dividend tax rates (8.75%/33.75%), combined with the ability to avoid the Personal Allowance taper by retaining profits in the company. Note that the sole trader at £120,000 is caught in the 60% trap, losing their Personal Allowance, while the company director can keep their salary at £12,570 and avoid this entirely.

Beyond Tax: Other Considerations

Limited Liability

A limited company provides a legal shield between your personal assets and business debts. If the company fails, creditors generally cannot pursue your personal savings, home, or other assets (unless you have given personal guarantees). As a sole trader, you are personally liable for all business debts without limit.

IR35 and Off-Payroll Working

If you provide services to clients through your limited company, IR35 legislation may apply. If HMRC (or your client, for medium/large organisations) determines that you would be an employee if you were engaged directly, your company's income from that engagement is taxed as employment income — eliminating the tax advantages of the limited company structure. Since the off-payroll working rules were extended to the private sector in April 2021, many contractors have found that IR35 significantly reduces the tax benefits of operating through a limited company.

Profit Retention

A limited company can retain profits within the business, paying only 19% Corporation Tax (for small profits). This can be advantageous if you want to build up reserves, invest in the business, or smooth your personal income across tax years. A sole trader must pay income tax and NIC on all profits in the year they arise, regardless of whether the money is drawn from the business.

Administrative Burden

Running a limited company involves significantly more administration:

• Annual accounts must be filed at Companies House
• A Corporation Tax return (CT600) must be filed with HMRC
• A Confirmation Statement must be filed annually
• The director must file a personal Self Assessment return
• PAYE must be operated for any salary payments
• Records of board decisions, share allotments, and other statutory documents must be maintained
• Professional accountancy fees are typically £1,000–£2,500 per year (versus £250–£500 for a sole trader)

Pension Contributions

Both sole traders and company directors can make pension contributions, but the mechanics differ. A company can make employer pension contributions that are deductible from Corporation Tax and not subject to NIC — this can be a very tax-efficient way of extracting profits. A sole trader makes personal contributions that attract income tax relief but do not reduce NIC liability.

When Should You Incorporate?

Based on our analysis, the general guidance for 2025/26 is:

• Below £50,000 profit: Stay as a sole trader. The tax savings from incorporation are negligible or negative, and the additional costs and complexity are not justified.
• £50,000–£80,000 profit: Consider incorporation, especially if you value limited liability, plan to retain profits, or have other income that pushes you into higher tax bands.
• Above £80,000 profit: Incorporation is almost certainly beneficial. The tax savings significantly exceed the additional costs.
• IR35 caught: If most of your income falls within IR35, incorporation offers limited tax advantages. You may be better off as a sole trader or employee.
• Multiple shareholders: If you have a spouse or partner who can legitimately hold shares and receive dividends, the tax savings from incorporation can be dramatically increased by splitting income between shareholders.