Teacher on £40,000

Sole Trader. Age 40. Plus £15,000 of other personal income stacking below. Pension preference: modest.

Every figure on this page is computed at build time by the same engines that power the live salary–dividend split, take-home and SIPP optimiser calculators. Inputs come from a single CSV row; outputs come from the engines. No static lookup tables, no hand-coded numbers.

Net cash

£30,106

Pension

£0

Effective rate

19.7%

Marginal rate

46%

Teacher vs Ltd Co director at £40,000 — what changes

The decision a teacher faces at £40,000 of income for 2026/27 is rarely "which calculator do I use" — it is "which legal structure leaves the most money in my pocket after tax." This page resolves the question for one specific scenario by running the relevant engines side-by-side at build time, so every number that follows is reproducible from a single CSV row and the BracketMath source code.

On the sole-trader route, taxable profits are £38,000 after the trading allowance / actual expenses decision, producing £30,106 of net cash after income tax + Class 4 + voluntary Class 2.

Incorporating instead — Ltd Co at the same turnover and expense pot — would produce £27,949 of net cash. The gap of £2,157 is in favour of the sole-trader route — at this turnover level the corporation-tax + dividend stack offers no edge over self-assessment. Against that gap, weigh the ~£800–£1,500/yr accountancy overhead, the public Companies House filing burden, and the loss of the trading allowance.

For a complete walk-through of the optimisation for this specific scenario, see the comparison table further down this page.

The numbers, line by line

Turnover	£40,000
Taxable profits	£38,000
Trading allowance vs actual expenses	Actual expenses
Income tax	£6,189
Class 4 NI	£1,526
Class 2 NI (voluntary)	£179
Net cash (year)	£30,106
Net cash (monthly)	£2,509
Hours-equivalent at NLW (£12.21/hr)	2,466 hrs
Effective rate	19.7%
Same turnover as Ltd Co (no pension)	£27,949
Incorporate vs stay sole trader	£2,157 for staying sole trader

Why this scenario is different

Compared to the closest peer profile — Freelance designer at £40,000 — this scenario sits £0 higher on gross income. That moves net cash by −£1,103, the pension contribution by +£0, and the effective rate by +2.8%. The shift in effective rate is large enough that the binding tax constraint has changed — probably crossing a band boundary. Taxable profits change from £38,000 to £38,000 (after the trading-allowance / actual-expenses choice).

Questions this scenario raises

Why is the effective rate lower than the headline tax brackets?

Because the headline 20% / 40% / 45% rates apply only to the income slice in each band — not the whole income. The Personal Allowance shelters the first £12,570 at 0%; the basic-rate band only charges 20% on the next £37,700; and so on. The effective rate on the entire income is the weighted average of every slice — typically much lower than the headline number people quote.

Should I pay voluntary Class 2 NI even if my profits are below the threshold?

Usually yes. Class 2 voluntary contributions cost £179.40/yr (£3.45/week × 52) and buy a State Pension qualifying year. The Full New State Pension as of 2026 is £230.25/wk (£11,973/yr) and you need 35 qualifying years to get the full amount. One year of voluntary Class 2 buys roughly £342 of annual State Pension at retirement — a payback period of about 6 months on first claim.

When does the £50,270 higher-rate threshold start to bite a sole trader?

Once total taxable income (trading profits + other income, after the Personal Allowance) exceeds £37,700. At that point, each £1 of additional trading profit is taxed at 40% income tax + 2% Class 4 NI = 42% combined marginal. This is also the point at which "should I incorporate?" tends to start producing a meaningful answer.

How does my PAYE day job interact with this side-hustle income?

For this row there is £15,000 of other personal income stacking below the self-employment figure. The PAYE / other income uses the Personal Allowance first, then the basic-rate band, then the higher-rate band — the self-employment income is "stacked" on top and taxed at whichever marginal rate it lands in. That is why low self-employment income can still attract 40% tax if the PAYE income is large enough to push the marginal slice into higher rate.

What expenses can I deduct as a sole trader?

"Wholly and exclusively" business costs — equipment, software, professional insurance, travel to non-permanent workplaces, training that maintains existing skills, a proportionate share of home-office costs (HMRC simplified flat rates available), and accountancy fees. Personal commuting, entertainment, training to acquire new skills, and clothing (unless protective / uniform) are not deductible.

Methodology

Income tax, National Insurance and Corporation Tax bands taken from HMRC's 2026/27 rates and allowances tables (gov.uk/.../income-tax; corporation-tax). Pension Annual Allowance and taper rules from Finance Act 2004 / 2023. Trading allowance per ITTOIA 2005 s.783A. Voluntary Class 2 figure (£179.40/yr = £3.45/wk × 52) from HMRC voluntary NI guidance.

Style: 2026/27 tax year throughout; figures rounded to whole pounds in the user-facing prose; effective rates computed as (deductions / gross). The voice is methodological — no first person, no claimed credentials, no marketing fluff.

This page is not personalised advice; for advice regulated by the FCA, consult an adviser registered with the Financial Conduct Authority. See the full disclaimer.