Sole trader or limited company: what actually decides it

Most people come to this looking for a number: the profit at which a limited company starts to pay. The number exists, roughly. It moves every April, and it rarely decides anything. Some incorporate where the saving barely covers the extra accountancy fee; others stay sole traders a year too long because nobody told them most recruitment agencies will not engage an individual.

The saving comes from National Insurance and timing

As a sole trader you pay income tax and Class 4 National Insurance on your profit. Incorporate, and the company pays corporation tax while you are taxed again on what you take out, but dividends carry no National Insurance and you choose when to take them. If you are a Scottish taxpayer, your profit is taxed at Scottish rates and bands while dividends stay at UK rates, so the balance between the two falls in a different place than it does in England.

Both advantages are thinner than they were. Dividend tax rose again from April 2026 at the basic and higher rates, not the additional rate. Corporation tax is no longer one rate either: a lower rate for small profits, a higher main rate, and a marginal band between them where each extra pound is effectively taxed above the main rate. Current figures sit on gov.uk for corporation tax, dividends and self-employed National Insurance.

You are taxed on profit you never touched

A sole trader's profit is taxed in the year it is earned, spent or not. Company profit is taxed at the corporation tax rate and stays there until you draw it. So the test is not turnover; it is how much you can leave behind. Draw everything you make to live and the advantage shrinks to National Insurance alone. If the business produces more than you need — a reserve, equipment — the deferral is worth real money, and it repeats every year.

Limited liability covers less than the brochure implies

The separation is real: if the company cannot pay its debts, creditors generally cannot come to you. But the exposures that sink small businesses are carved back out. A landlord or lender dealing with a company with no trading history will usually want a personal guarantee, or a charge over something you own. Draw money as a loan and, if the company fails, the liquidator will ask for it back. And the risk most professionals meet, a negligence claim, needs professional indemnity insurance either way.

Your clients may have decided this already

If any of your work comes through agencies, the choice is largely made. Agency legislation can leave the agency responsible for PAYE on a self-employed worker it places, so most will not engage a sole trader: limited company, umbrella, or their own payroll. Since April 2026 the agency, not the umbrella, answers for PAYE in an umbrella chain, so that preference has hardened. Work direct with the public or small businesses and none of it touches you.

A company is no escape from employment-status questions either. The off-payroll rules look at how you actually work, not what your invoice says: a medium or large client decides your status and can deduct tax before paying your company, a small client leaves that judgement with you. The thresholds behind that size test rose for financial years from 6 April 2025, but a client's status only moves once those accounts reach their filing deadline, so for most clients the widened test first applies in 2027-28, not yet.

The admin gap is closing from both ends

A company means accounts at Companies House, a corporation tax return to HMRC on its own deadline, a confirmation statement, a separate bank account, a payroll scheme once you pay yourself enough to need one or take on anyone else, and a Self Assessment return once you take dividends or other untaxed income, as most directors do. Directors and people with significant control must now verify their identity with Companies House and quote a personal code on filings, which takes longer if your documents are not British.

The sole trader's quiet life is ending too. Making Tax Digital for Income Tax began in April 2026 for the highest qualifying incomes and steps down in 2027 and 2028, replacing one annual return with quarterly updates sent from software.

The return trip is the expensive one

Going in, you sell your business to a new legal person. Assets move at market value, which can produce a chargeable gain, and incorporation relief can defer it. For transfers from 6 April 2026 it must be claimed within a time limit, not applied automatically as it once was. Contracts, leases, licences, insurance, bank mandates and VAT registration belong to the old business and must be re-signed.

Coming back out, there is no matching relief. Money and assets are taxed on the way: dividends while the company trades, a capital distribution if you liquidate properly. Dissolve it without a formal liquidation and anything above a modest limit is taxed as income instead. Wind it up and carry on the same or a similar trade within two years, and that distribution can be recharacterised as income under a rule written for exactly that. Treat incorporation as a decision you intend to keep for three or four years.

The costliest mistake is not a structural one

It is paying yourself a small salary and modest dividends for three years because it was efficient, then applying for a mortgage. Lenders treat a director with a material shareholding as self-employed and assess declared income, salary plus dividends, ignoring profit left inside the company; the level is lender policy, not law. People cut declared income by tens of thousands to save a few thousand in tax, then cannot borrow — and accounts cannot be rewritten. If a mortgage, a visa or anything income-tested is coming in the next three years, set your drawings around it and tell whoever prepares your accounts before the year end, not after.

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This is general information about how a process works, not advice about your situation. Thresholds, fees and deadlines change — check the official source linked above for the current figures, or ask a professional who can see your circumstances.