Builder on £65,000

Sole Trader. Age 44. 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

£46,947

Pension

£0

Effective rate

22.8%

Marginal rate

42%

Net pay for a builder with £65,000 of turnover

A builder operating as a sole trader with £65,000 of turnover for 2026/27 has taxable profits of £61,750 after the actual business expenses. Income tax on those profits comes to £12,132; Class 4 NI (6% / 2%) comes to £2,492; and the voluntary Class 2 contribution at £179.40 buys a State Pension qualifying year on top.

Net cash after tax + NI: £46,947. Effective rate on turnover: 22.8%. Marginal rate on the next £1 of trading profit: 42%.

The recurring "should I incorporate?" question: at this turnover, a Ltd Co (no pension, same expense pot) would deliver £47,821 net — £874 more than the sole-trader route. There is no clean intersection in the £15k–£400k range examined — one route dominates throughout.

The numbers, line by line

Turnover	£65,000
Taxable profits	£61,750
Trading allowance vs actual expenses	Actual expenses
Income tax	£12,132
Class 4 NI	£2,492
Class 2 NI (voluntary)	£179
Net cash (year)	£46,947
Net cash (monthly)	£3,912
Hours-equivalent at NLW (£12.21/hr)	3,845 hrs
Effective rate	22.8%
Same turnover as Ltd Co (no pension)	£47,821
Incorporate vs stay sole trader	+£874 for Ltd Co

Why this scenario is different

Compared to the closest peer profile — NHS doctor at £65,000 — this scenario sits £0 higher on gross income. That moves net cash by +£4,109, the pension contribution by +£0, and the effective rate by −6.3%. The shift in effective rate is large enough that the binding tax constraint has changed — probably crossing a band boundary. Taxable profits change from £61,750 to £61,750 (after the trading-allowance / actual-expenses choice).

Questions this scenario raises

Is this calculation valid for the 2027/28 tax year?

Only partially. Thresholds (PA, basic-rate, higher-rate, NI thresholds) are frozen through April 2028 per the Autumn Budget 2024. Some rates may change at the Spring 2027 Budget. The figures here are accurate for 2026/27 and will be re-run after any future Finance Act changes — check the published-date footer of this page.

How do I model my partner's income alongside mine?

BracketMath models a single tax entity — there is no joint-couple calculation. For couples, the practical approach is to run each partner separately and consider income-splitting strategies (employing the lower-earning spouse for genuine work performed, sharing dividends if both are shareholders, etc). The Ltd Co spousal share pattern is sketched in /guides/ltd-company-director-tax.

Are the engine assumptions documented anywhere?

Yes — every constant lives in src/lib/tax/constants.ts with a source-URL comment. Every engine function is unit-tested against HMRC examples (180+ test cases). The full methodology is at /about and the per-engine assumptions are spelled out at the foot of each calculator.

Are the numbers on this page computed live or pre-rendered?

They are pre-rendered at build time by running the BracketMath engine code against the inputs for this specific row. That means: zero JavaScript on the page for the calculation itself, the figures cannot drift if the engine is changed, and you can verify them by running the corresponding calculator with the same inputs.

What does the "marginal rate" mean on this page?

It is the rate paid on the next £1 of gross income added to this scenario. For this row that figure is 42.0%. The marginal rate is always higher than the average effective rate — it is the right number for "is one more invoice worth it" decisions.

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.