Software contractor on £110,000

Inside-IR35 Umbrella. Inside IR35. Age 34. 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

£61,771

Pension

£5,500

Effective rate

38.8%

Marginal rate

42%

Inside-IR35 take-home for a software contractor at £500/day

A software contractor on an inside-IR35 umbrella contract at £500/day, billing 220 days/year, has a gross contract value of £110,000. The umbrella deducts its fee (£1,500/yr assumed), employer National Insurance at 15% above the £5,000 Secondary Threshold, then runs the remainder through PAYE — income tax at 20% / 40% / 45% rUK bands plus employee NI at 8% / 2%.

What the contractor actually takes home: £61,771 of net cash, plus £5,500 into a pension via salary sacrifice (the only meaningful tax-saving lever inside IR35). Total deductions through the chain: £42,729 — an effective rate of 38.8% on the contract value.

For comparison, the same contractor outside IR35 — same day rate, same days, same expenses, same pension preference — would take home £67,030 of net cash plus £5,500 into a pension. That's £5,259 more in cash plus £0 more into pension per year. To match the outside-IR35 cash on this inside contract, the day rate would need to rise to £551 — that is the negotiating number.

The numbers, line by line

Day rate	£500
Contract value (220 days)	£110,000
Inside-IR35 net cash	£61,771
Inside-IR35 pension	£5,500
Outside-IR35 net cash	£67,030
Outside-IR35 pension	£5,500
Cost of being inside IR35 (net wealth)	£5,259
Break-even outside-IR35 day rate	£551

Why this scenario is different

Compared to the closest peer profile — IT contractor at £110,000 — this scenario sits £0 higher on gross income. That moves net cash by +£0, the pension contribution by +£0, and the effective rate by +0%. The effective rate moves only modestly — both scenarios sit inside the same binding tax band. The break-even outside-IR35 day rate moves from £551 to £551 per day.

Questions this scenario raises

Is the Apprenticeship Levy actually due on my umbrella rate?

Legally, only if the umbrella's total annual paybill exceeds £3 million — and even then it falls on the umbrella, not the contractor. In practice many umbrellas pass it through as a 0.5% deduction. This page models the levy as off by default; toggle it on in the take-home calculator to see the effect.

Where does the BracketMath engine source its rates?

Income tax / NI / CT / dividend rates come from HMRC's published 2026/27 rate tables (gov.uk/government/publications/rates-and-allowances-income-tax). Pension rules come from FA 2004 and the FCA's consumer guidance. Historical investment returns used in the Monte Carlo engine come from a 125-year UK gilt + UK equity series stored in src/data/historical-returns.json. Every constant carries a source URL in the source code.

What is the cost of being inside IR35 vs outside at this day rate?

For this row, operating inside IR35 instead of outside costs £5,259 per year of net wealth (cash + pension). To match the outside-IR35 take-home at the same day rate, an inside contract would need to be priced at approximately £551/day.

What if I have rental income alongside this self-employment?

Add it to the `otherIncome` field of the calculator. Property income is taxed at non-savings, non-dividend rates (so stacks alongside salary in the band schedule). The first £1,000 of rental income can also be sheltered by the separate Property Allowance under FA 2017 s.16.

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.