Sole Trader vs Limited Company at £50K: Where the Maths Tips

"Once you hit £50K, you should incorporate." Most accountants have repeated some version of this for the past decade. For a long time the rule roughly held: above £50,000 of profit, a limited company shaved £2,000 to £4,000 a year off the tax bill compared to sole trader status. Below £50K, the extra paperwork tipped the scales the other way.

That rule was true. It is no longer reliably true.

This guide is written by LOYALS, a King's Cross firm of chartered accountants and business consultants that handles company formation, corporation tax and salary-and-dividend planning for London owner-managers. Three changes have undone the old maths. First, in April 2023 the small profits corporation tax rate of 19 percent was capped at the first £50,000 of company profit, with an effective 26.5 percent charged above that, per HMRC's corporation tax rates and marginal relief guidance. Second, employer National Insurance rose to 15 percent from April 2025 with the secondary threshold cut to £5,000. Third, from 6 April 2026 the dividend ordinary rate rose from 8.75 percent to 10.75 percent, and the upper rate from 33.75 percent to 35.75 percent. All three pull money out of the limited company column.

The result is a comparison that no longer behaves the way the textbooks say. At £50,000 of profit in the 2026/27 tax year, the sole trader comes out ahead. The tipping point still exists, but it now sits higher than most people expect and it is far narrower than the old rule suggested. For how this plays out in one sector, see our guide on sole trader vs limited company for a domiciliary care provider.

Why the £50K rule of thumb stopped working

Before the April 2023 reform, every UK limited company paid 19 percent corporation tax on the full slice of its profits up to £300,000. That single rate was the engine of the sole trader vs limited company comparison. Move profit out of the higher-rate income tax band (40 percent above £50,270) into corporation tax at 19 percent, then drip-feed it out as dividends, and the saving was structural.

From April 2023, the 19 percent rate only applies to companies with profits up to £50,000. Profits between £50,000 and £250,000 fall into marginal relief, which works out at 26.5 percent on the slice above £50K. The full main rate of 25 percent applies above £250,000.

So a director who used to convert £30,000 of higher-rate-taxable income into 19 percent corporation tax now pays 26.5 percent on most of it. That is a 7.5 percentage point swing, worth about £2,250 a year of lost saving on £30,000 of profit above the threshold.

A third drag often gets missed: employer National Insurance. It rose to 15 percent from 6 April 2025 and the secondary threshold was cut to £5,000, as set out in HMRC's National Insurance rates and categories. Even a bare £12,570 director's salary now carries £1,136 of employer NIC, and a lone director does not qualify for the Employment Allowance. A sole trader never pays that. Stack the three reforms together and the headline tax advantage of incorporation has narrowed by anywhere from £1,500 to £4,000 a year for typical owner-managers.

None of this makes limited companies bad. It means the headline tax saving at £50,000 of profit, taking salary and dividends only, has effectively gone.

The maths at £50,000 profit, 2026/27 rates

Let's run the comparison cleanly. Assume £50,000 of net business profit, no other income, no pension contributions, no retained profits in the company, full extraction. England, single director, no Employment Allowance.

Sole trader at £50,000 profit

The personal allowance covers the first £12,570. The next £37,430 sits in the basic rate band at 20 percent income tax, giving £7,486. Class 4 National Insurance runs at 6 percent on profits between £12,570 and £50,270, which is £2,246 on the same slice, per HMRC's self-employed National Insurance rates. Class 2 was abolished from April 2024, so there is nothing else to add.

Total HMRC bill: £9,732. Take-home: £40,268.

Limited company at £50,000 profit

The director takes a £12,570 salary, which uses up the personal allowance. Employer National Insurance is due at 15 percent on the slice above the £5,000 secondary threshold (£12,570 minus £5,000 equals £7,570), giving employer NIC of £1,136. Salary plus employer NIC of £13,706 is deductible against corporation tax, leaving £36,294 of taxable company profit. That sits below the £50,000 small profits cap, so it is taxed at 19 percent, giving corporation tax of £6,896.

The £29,398 left after corporation tax is paid out as a dividend. The £500 dividend allowance covers the first slice tax-free, per HMRC's guidance on tax on dividends. The remaining £28,898 sits in the basic rate band at the 10.75 percent dividend ordinary rate, giving £3,106 of personal dividend tax.

Total HMRC bill: corporation tax £6,896, plus employer NIC £1,136, plus dividend tax £3,106, equals £11,138. Take-home: £38,862.

The result will surprise anyone who last ran the numbers in 2022. For a single-director company on the standard salary-plus-dividends route, the limited company is now the more expensive structure at exactly the profit level the old rule said you should incorporate.

The full picture across profit levels

What about £40K, £60K, £70K, £80K? The shape of the comparison is more interesting once you lay it out. Below is the same methodology applied across a range of profit levels for the 2026/27 tax year, full extraction, identical assumptions throughout.

Read the right-hand column carefully. On a pure full-extraction tax comparison, the sole trader is ahead or level at every point across this range. The two routes come closest around £60,000 of profit, where they land within about £20 of each other, but the £2,000-plus company saving that practitioners used to quote has gone. The narrow band where a company briefly won on the old maths no longer exists once 15 percent employer NIC is in the model.

The reason for the dip and recovery is the interaction between corporation tax marginal relief at 26.5 percent and the higher post-2026 dividend rates. Once company profit (after salary) crosses the £50,000 small profits cap, every extra pound attracts effective corporation tax of 26.5 percent, then a further 10.75 percent dividend tax in the basic rate band or 35.75 percent at higher rate. The combined extraction rate of roughly 34 to 43 percent compares badly with sole trader Class 4 NIC at 2 percent above £50,270 sitting on top of 40 percent income tax.

When a limited company still wins at £50K profit

None of this means you should stay sole trader. The headline tax bill is one input in a structure decision, and at £50K of profit there are several scenarios where the company is still the right answer. The same trade-off plays out by profession, and our guide on what an accountant costs for a lorry driver shows how the choice looks for owner-drivers.

1. You are not extracting all the profit

If you can leave £15,000 inside the company at the 19 percent small profits rate, you defer the dividend tax until a year when your other income is lower: a parental leave year, a sabbatical, or after retirement. The deferred extraction can save thousands depending on timing. A sole trader has no equivalent lever. All profit is taxed in the year it is earned.

2. You are making serious pension contributions

Employer pension contributions through a company are corporation tax deductible with no National Insurance drag. A £15,000 employer contribution costs the company £15,000 of deductible expense, so the real cost is roughly £12,150 after corporation tax relief. A sole trader making the same £15,000 personal contribution gets income tax relief but no NIC relief, so the comparable real cost is around £9,000 net for a 40 percent taxpayer or £12,000 for a 20 percent taxpayer. The company route catches up sharply when pensions are in the picture, especially for higher-rate sole traders planning large contributions.

3. You need limited liability

If you take on contracts where things can go wrong (construction, food, healthcare, advisory work that touches client money), the personal asset protection of a company is meaningful. A sole trader's house is on the line for business debts. A director's house is not, except in specific circumstances. That protection has a real value a tax comparison never shows.

4. Your customers expect it

Some sectors strongly prefer limited companies. Procurement teams at larger clients often will not engage sole traders. CIS subcontractors chasing gross payment status find the trading-history tests easier to evidence with company accounts. Recruitment agencies for IT contractors typically deal only with limited companies, and NHS framework agencies operate the same way for clinical locums, though the IR35 status determination then drives the take-home maths. For the locum picture see our IR35 for locum doctors and dentists guide. If your sector treats a company as a credibility signal, that converts into more work, and the maths above does not capture more work.

5. You are planning to sell or bring in investors

You can sell shares in a limited company, and Business Asset Disposal Relief (formerly Entrepreneurs' Relief) reduces the capital gains tax on qualifying share disposals to 18 percent for 2026/27, up from 14 percent in 2025/26 and 10 percent before April 2025, on the first £1 million of lifetime gains, per HMRC's Business Asset Disposal Relief guidance. A sole trader sells assets, not shares, and hands the buyer a less clean structure. Anyone eyeing an exit in the next five years should model with that endpoint in mind.

What this means for you

If you are sitting on profits in the £40,000 to £60,000 range and someone tells you incorporating will save you four-figure sums, ask them to show you the working. The 2026/27 numbers do not support that conclusion any more.

If you are already a limited company at this profit level and extracting everything, you are not necessarily worse off, but you are also not getting the tax saving incorporation once promised. The case for staying incorporated rests on liability, retained profits, pension funding or a planned exit, not the headline tax comparison.

If you are a sole trader being told you must incorporate by April 2026 because of Making Tax Digital for Income Tax, that is an admin argument, not a structural one. MTD ITSA is mandatory for gross income above £50,000 and does add cost (software plus quarterly filings), per HMRC's Making Tax Digital for Income Tax guidance, but on a like-for-like basis those costs usually come to less than the dividend tax you would pay extracting through a company.

The right answer depends on your own position: forecast profit, pension plans, family circumstances, contracting environment and exit horizon. If you want the maths run for your own figures, LOYALS models the sole trader and limited company routes side by side, in writing, before you decide. Do not act on a rule that has not been current since the April 2023 corporation tax reform.

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