Sacrifice £5,000 from a £50,000 salary and your take-home falls by just £3,600 — yet a full £5,000 lands in your pension. That's a £1,400 effective gain: £1,000 Income Tax and £400 National Insurance you no longer pay. Try your own numbers below.
Salary + sacrifice → take-home & gain
With salary sacrifice you formally give up part of your gross salary, and your employer pays that money straight into your pension instead. Because the money never counts as your salary, it escapes both Income Tax and National Insurance. A normal "relief at source" pension contribution only saves the Income Tax at basic rate up front — the NI saving is what makes sacrifice the more efficient route for most employees.
Worked example for the headline figure: start on £50,000. Your take-home before sacrifice is £39,519.60. Sacrifice £5,000 and your new salary is £45,000, giving take-home of £35,919.60. So your pay actually drops by £3,600 — but £5,000 went into your pension. The difference, £1,400, is the tax and NI you saved: £1,000 of Income Tax at 20% plus £400 of National Insurance at 8%.
The saving depends on the tax and NI band the sacrificed slice sits in. For 2026/27:
| Your band | Income Tax saved | NI saved | Total per £100 |
|---|---|---|---|
| Basic rate (to £50,270) | 20% | 8% | £28 |
| Higher rate (above £50,270) | 40% | 2% | £42 |
| Additional rate (above £125,140) | 45% | 2% | £47 |
Salary sacrifice is powerful but it isn't free of side-effects:
Sacrificing £5,000 from a £50,000 salary puts £5,000 into your pension but only reduces your take-home by £3,600, because you save £1,000 Income Tax (20%) and £400 National Insurance (8%). The £1,400 you save is your effective gain.
Yes. Because the money comes off your gross salary before NI is worked out, you save employee National Insurance as well as Income Tax. Your employer saves their NI too and sometimes adds it to your pension, boosting the gain further.
A lower gross salary can reduce mortgage borrowing and earnings-related benefits such as statutory maternity pay, and you can't sacrifice below the National Minimum Wage. For most higher earners the tax and NI savings outweigh these effects.
Usually, yes — the extra NI saving makes it more efficient than a relief-at-source contribution of the same size. Check your employer offers it and that your reduced salary still meets any mortgage or benefit needs. See GOV.UK for the rules.
