Salary sacrifice is one of the few genuinely free wins in personal finance, and most people who could use it do not. The idea sounds counterintuitive — agree to a lower salary — but what you are really doing is rerouting money into your pension before tax and National Insurance can touch it, often with your employer chipping in their saving too. Done right, it turns roughly £100 of "lost" salary into noticeably more than £100 in your pension. Here is exactly how it works in 2025/26.
- You swap part of your gross salary for a pension contribution, so it is never taxed as income.
- You save income tax and employee National Insurance on the sacrificed amount.
- Many employers pass back their 15% employer NI saving too, boosting your pot further.
- Your take-home falls by less than the amount contributed — the taxman funds the gap.
What salary sacrifice actually is
In a normal pension, you pay in from your take-home pay and claim some tax back. With salary sacrifice, you formally agree to a lower salary, and your employer pays the difference directly into your pension. Because that money never counts as your salary, it is never subject to income tax or National Insurance in the first place. It is the same destination — your pension — reached by a more tax-efficient route.
The savings, line by line
Say you sacrifice £100 of monthly salary. As a basic-rate taxpayer you would otherwise have paid:
- 20% income tax on that £100 = £20.
- 8% employee NI = £8.
So that £100 of gross salary was only ever going to be £72 in your pocket. Through sacrifice, the full £100 goes into your pension instead. Your take-home drops by just £72, but £100 lands in your pot — an instant uplift before any investment growth.
For a higher-rate taxpayer it is even better: 40% tax plus 2% NI means £100 into the pension costs only about £58 of take-home.
The employer NI bonus
Here is the part that makes salary sacrifice better than an ordinary pension. When you sacrifice salary, your employer also saves their National Insurance — 15% in 2025/26 — on the amount. Generous employers pass some or all of that saving into your pension on top. On a £100 sacrifice that is up to another £15, so £115 could land in your pot for your £72 of foregone take-home. Always check your scheme's rules to see whether the employer NI saving is shared.
A worked example
Take someone earning £45,000 who decides to sacrifice 5% of salary — £2,250 a year — into their pension:
Salary for tax drops from £45,000 to £42,750.
Tax and NI saved on the £2,250
about 20% + 8% = roughly £630.
Net take-home cost
about £1,620 for the year.
Into the pension
the full £2,250, plus any shared employer NI saving.
So roughly £1,620 of reduced take-home becomes £2,250+ of retirement savings. Model the long-term effect with the pension calculator, and check the take-home impact on the take-home pay tool.
The traps to watch
Salary sacrifice is powerful but not for everyone:
You cannot sacrifice below the minimum wage Salary sacrifice cannot reduce your effective pay below the National Minimum Wage. If you are a lower earner, your employer may have to limit or refuse the sacrifice. This is the most common reason a scheme cannot be used in full.
Other points to keep in mind:
- A lower headline salary can affect mortgage borrowing, life cover based on salary, and statutory payments like maternity pay — though pension contributions are usually viewed favourably by lenders.
- It only helps if your employer offers a salary sacrifice scheme; not all do.
- Contributions still count toward the annual allowance (usually £60,000), so very large sacrifices need checking.
Why it is the smartest use of a pay rise
If you get a raise and do not need all of it, sacrificing the extra into your pension is often the most efficient thing you can do with it — especially if the rise pushes you over a threshold like £50,270 or £100,000, where each pound is taxed much harder. Sacrificing enough to drop back under the line can be worth far more than the contribution itself. It is the same lever, used deliberately.
Frequently asked questions
You give up part of your gross salary in exchange for an employer pension contribution, so that money is never taxed as income or subject to National Insurance. Your take-home falls by less than the amount contributed.
For a basic-rate taxpayer, about £72 of take-home for every £100 into the pension; for a higher-rate taxpayer, around £58 — before any employer NI saving is added.
When you sacrifice salary, your employer saves their 15% National Insurance on it. Many employers add some or all of that saving to your pension, making salary sacrifice more generous than a standard pension contribution.
Only if your employer offers a scheme, and only down to the National Minimum Wage. Lower earners may be limited, and you should check the effect on mortgage applications and statutory pay.
Sacrifice usually keeps you above the level needed to protect your State Pension record, but very large reductions for low earners should be checked, as National Insurance credits depend on earnings.
Figures are 2025/26 estimates for England, Wales and Northern Ireland. Salary sacrifice rules and scheme terms vary by employer — check yours and take advice for large contributions.