Sophie Clarke
Choosing how to trade is one of the first big decisions you will make as a business owner, and it is rarely a case of one option being better than the other. A sole trader structure suits some businesses beautifully; a limited company can save others thousands of pounds a year in tax. The right answer depends on your profits, your appetite for paperwork, the risks you carry and where you want the business to go.
The tax picture: where the real difference lies
As a sole trader, your business profits are your income. You pay income tax at 20%, 40% or 45% depending on how much you earn, plus Class 4 National Insurance at 6% on profits between £12,570 and £50,270, and 2% on anything above that. Class 2 was effectively withdrawn for most self-employed people from April 2024, though you still build up National Insurance credits for the state pension if profits exceed the small profits threshold.
A limited company is taxed differently. Corporation tax is 19% on profits up to £50,000, rising to 25% once profits exceed £250,000, with marginal relief tapering in between. The company pays tax on its profits, and you then take money out — usually a mix of a director's salary and dividends. Dividends carry their own tax rates of 8.75%, 33.75% and 39.35%, with only the first £500 of dividend income tax-free.
The upshot is that a sole trader earning £30,000 keeps more than a limited company owner taking the same amount in dividends, because a limited company brings extra costs. Once profits climb beyond roughly £40,000 to £50,000, the corporation tax and dividend combination usually starts to win, particularly where profits are retained in the business rather than drawn out.
Personal liability and legal responsibilities
As a sole trader, there is no legal separation between you and your business. If the business is sued, cannot pay a supplier or defaults on a loan, your personal assets — your home, savings and car — are on the line. That is the single biggest argument in favour of incorporating, and it matters most in trades, construction, manufacturing and any business with physical risk or large contracts.
A limited company is a separate legal entity. Your personal liability is generally limited to any shares you own and any personal guarantees you have signed, although you still owe duties as a director. Those duties are real: you must act in the company's best interests, keep proper records, avoid trading while insolvent and file accounts and confirmation statements on time. Directors can be personally pursued for breaches, so incorporation is not a licence to ignore governance.
There is also the question of how you present yourself. Some larger clients, particularly in the public sector, will only engage a limited company. A limited company name is protected, which matters if you are building a brand you might one day sell.
Administration and ongoing costs
Sole trader bookkeeping is comparatively light. You need to report profits on a Self Assessment tax return, which is due by 31 January following the tax year end, and you may have to make payments on account in January and July if your tax bill exceeds £1,000. You can use the £1,000 trading allowance instead of claiming expenses if your costs are small.
A limited company has more moving parts. Expect:
- Annual accounts filed with Companies House, usually within nine months of your year end
- A CT600 corporation tax return, due 12 months after the period end, with tax payable nine months and one day after
- A confirmation statement each year, even if nothing has changed
- Payroll and Real Time Information submissions if you pay yourself a salary
- VAT registration once turnover passes £90,000, or voluntarily if it suits you
Accountancy fees typically run from a few hundred pounds a year for a straightforward sole trader to £1,000 or more for a limited company with payroll, VAT and dividends. Add accounting software, and the gap widens further. These costs are real, but they are usually deductible and often modest set against the tax saved.
Practical considerations beyond the numbers
Think about how you want to work. If you contract through agencies, IR35 rules may push you towards — or away from — a limited company depending on the client's status determination. If you plan to bring in a business partner or investor, a limited company makes it straightforward to issue shares. If you want to sell the business one day, a limited company with a clean trading history is far easier to sell than a sole trade.
Pensions are worth a mention. An employer pension contribution from a limited company is a deductible business expense, which is a tax-efficient way to extract profit without triggering dividend tax. It is a strategy sole traders cannot replicate in the same way.
Changing structure later
You are not locked in. Thousands of sole traders incorporate each year, and it is a well-trodden path. The process involves registering with Companies House, transferring assets and contracts, and notifying HMRC. Incorporation relief can defer capital gains tax on the transfer of the business to the company, but goodwill and asset valuations need care — transferring a van or equipment at the wrong value can create an unexpected tax charge.
Our honest advice is this: start simple. If you are testing an idea with modest profits and low risk, begin as a sole trader and keep your admin light. Once profits are consistently above £40,000 or so, or you need the protection and credibility of a limited company, take professional advice and make the switch properly. The right structure is the one that fits your business today and stretches comfortably into the next few years.
