The seven questions
Whether to start a limited company isn't a single tax-saving calculation — it's the answer to seven questions about your work, your profit level, and your risk tolerance. Walk through each.
Question 1 — What's your sustained annual profit?
The tax-efficiency switching point sits around £40,000-£45,000 of annual profit after accounting fees. Below that, sole trader is usually cheaper overall once you factor in the additional ~£1,500/year cost of running a limited company. Above £45,000, limited starts to win clearly — and the gap widens at higher profit levels (around £4,000 a year of saving at £100k profit, £11,000 a year at £150k).
Sustained is the key word. Limited makes sense if you expect £50,000+ for at least 2-3 years. For a one-off high-profit year on otherwise modest income, the formation and closure costs eat the benefit.
If you're not sure, use the Day Rate / IR35 Calculator to model both paths at your projected income.
Question 2 — What's your liability exposure?
This is the question most "should I incorporate" articles under-weight. Sole traders are personally liable for business debts and damages — their house, car, savings are at risk if a client successfully claims your work caused them losses.
Specific work types where this matters disproportionately:
- Software development with significant client systems involved
- Construction and trades where mistakes can cause property damage
- Legal, accountancy, financial advice (these usually require professional indemnity anyway, but Ltd adds a structural layer)
- Design work where IP infringement claims are possible
- Consulting at senior level for large clients
- Any work where a single client's success significantly depends on your output
Limited company protects your personal assets from claims against the business (provided you haven't given personal guarantees and haven't traded fraudulently). For high-liability work, that's worth the £1,500/year cost regardless of profit level.
Question 3 — Are you near or planning to be a higher-rate taxpayer?
The dividend tax advantage compounds at higher income levels. For total income inside the basic-rate band, the saving over sole trader is modest. At higher-rate territory (combined personal income above £50,270), the dividend rates (33.75% in higher band, 39.35% in additional band) are still lower than the combined Income Tax + Class 4 NI a sole trader pays (42% effective).
For high earners doing freelance / contracting work in their spare time alongside a salaried role, this matters less because the limited company income stacks onto employment income in your personal tax calculation.
Question 4 — Do you want to make large pension contributions?
This is where the limited company has its biggest single advantage. A Ltd can make employer pension contributions of up to the annual allowance (£60,000 in 2026/27) directly from company profits. These are:
- A Corporation Tax deduction for the company (reducing CT)
- Not counted as your personal income
- Outside the 100%-of-earnings cap that limits personal pension contributions
For a profitable Ltd with retained earnings, this can be one of the most tax-efficient long-term saving paths in the UK system. Sole traders have to use personal pension contributions, capped at 100% of relevant earnings, and the tax relief works differently (via Self Assessment).
If pension planning at higher contribution levels is part of your financial plan, Ltd has a clear advantage.
Question 5 — How much administrative overhead will you tolerate?
Limited company adds real ongoing admin:
- Bookkeeping (cloud accounting software automates most of this)
- Annual company accounts (your accountant prepares)
- Annual Corporation Tax return (CT600)
- Confirmation statement (one-page form, £34/year)
- Self Assessment for personal dividends + salary
- Monthly PAYE submission if you're paying yourself salary
- VAT returns if registered
Total time: typically 3-5 hours a month once set up, half of which is sense-checking your accountant has everything they need. Annual cost: £900-£1,800 for a contractor accountant.
If "I just want to do my work and not think about admin" is your default, sole trader keeps things simpler. If "I can spend a few hours a month on company admin to save more tax" sounds reasonable, Ltd is fine.
Question 6 — Do you need the money quickly?
Sole trader profit is your money the moment it lands in the business account. Move £5,000 to your personal account: it's just bookkeeping. No tax until Self Assessment time.
Limited company money is the company's money. To get it to you personally, you either:
- Take a director's salary (PAYE deductions apply)
- Declare a dividend (board minute required even as sole director; counts toward your personal Self Assessment)
- Take a director's loan (rules around timing and repayment apply)
For people who need flexible, immediate access to business income — paying for childcare from this month's invoice, covering an emergency — the limited company structure adds a layer of friction. For people who can plan their personal cashflow around quarterly or monthly dividend declarations, it's fine.
Question 7 — How important is professional credibility with bigger clients?
Some enterprise procurement teams won't engage with sole traders. The reasons are partly administrative (their vendor systems are built around limited companies) and partly risk-based (limited companies carry insurance and have a Companies House paper trail).
If your work is heading toward: - Larger UK enterprise clients - Public-sector contracts - Tendering for substantial projects - Working with US/multinational firms
…limited company is often a prerequisite, regardless of tax efficiency.
What the answers tell you
If you answered yes to Questions 2, 4, 5 or 7 OR your sustained annual profit is comfortably above £45,000, limited company likely makes sense.
If you answered no to all of those AND your profit is below £40,000, sole trader is probably the right call.
For everything in between, the Day Rate / IR35 Calculator gives you the specific cash-difference numbers for your situation, and sole trader vs limited company walks through the take-home comparison year-by-year.
Common mistakes when forming a Ltd
- Forming too early: at £25,000 of profit you're paying more in accountancy fees than you'd save in tax. Wait until profit is sustainable above £40k
- Not understanding IR35: if you're going to contract through your own Ltd, get clear on IR35 status before signing contracts (see inside vs outside IR35)
- No business bank account: HMRC requires Ltd company finances to be separate from personal — using your personal current account is non-compliant
- Taking dividends without retained earnings: dividends can only come from accumulated profits after Corporation Tax. Taking more than available creates "ultra vires" dividends that HMRC can treat as taxable income
- No accountant in year one: trying to do CT600 yourself can save £900/year but most first-time directors get one or two important things wrong. The accountant pays for themselves through avoided mistakes
Bottom line
Limited company makes sense for sustained higher-profit work, work with real liability exposure, or work where bigger clients require the structure. It doesn't make sense for early-stage low-profit operations or for people whose work is straightforward and low-risk.
If you've worked through the seven questions and Ltd is the answer, how to set up a limited company walks through the practical steps. For the direct numeric comparison, sole trader vs limited company shows the take-home difference at every profit level.