Salary Sacrifice Pensions: How They Work and What You Actually Save
By calculatemysalary.co.uk Editorial Team
Salary sacrifice pension schemes save you tax and National Insurance by reducing your gross pay. Here is how the numbers work in 2025/26.
Most people put money into their pension after tax has been taken off, then wait for HMRC to top it back up. Salary sacrifice skips that entire loop. Your employer reduces your contractual salary and puts the difference straight into your pension — before income tax or National Insurance is calculated.
The result: more goes into your pension, and less goes to the taxman. Both you and your employer pay less NI, and some employers pass their saving on to you as well.
How salary sacrifice actually works
You and your employer agree to lower your official salary. The amount you give up goes directly into your pension as an employer contribution. Because your gross pay is now lower, you pay less income tax and less National Insurance on every payslip.
It is a genuine contract change, not just a payroll trick. Your employment contract is amended, and all future pay references (P60, mortgage applications) will show the reduced figure.
HMRC has a full explanation at Salary sacrifice and the effects on PAYE.
Worked example: £35,000 salary, £200/month sacrifice
Say you earn £35,000 and decide to sacrifice £200 per month (£2,400 per year) into your pension.
Without salary sacrifice:
| Amount | |
|---|---|
| Gross salary | £35,000 |
| Income tax (20% on £22,430) | £4,486 |
| Employee NI (8% on £22,430) | £1,794 |
| Take-home pay | £28,720 |
If you then contributed £200/month from your net pay, your pension would receive £2,400, but the government would add basic-rate relief, making it £3,000 gross in the pot. Your actual take-home drops to £26,320.
With salary sacrifice:
| Amount | |
|---|---|
| Contractual salary | £32,600 |
| Income tax (20% on £20,030) | £4,006 |
| Employee NI (8% on £20,030) | £1,602 |
| Take-home pay | £26,992 |
| Pension contribution (from sacrifice) | £2,400 |
You take home £672 more per year — and the same £2,400 lands in your pension. That is the NI saving (8% of £2,400 = £192) plus the fact that relief is applied at source rather than needing to be claimed.
Your employer also saves. They no longer pay employer NI (15%) on that £2,400, saving £360 a year. Many employers add some or all of that saving into your pension too, so your pot could grow by up to £2,760 instead of £2,400.
Who benefits most
Everyone on a workplace pension scheme benefits from salary sacrifice if their employer offers it. But the savings scale up the more tax you pay:
- Basic-rate taxpayers save 8% in employee NI on every pound sacrificed.
- Higher-rate taxpayers save the NI plus 20% extra tax relief they would otherwise need to claim back via self-assessment. Salary sacrifice applies the relief automatically.
- Employers save 15% NI above the £5,000 threshold on every pound of salary sacrificed.
Ask your HR or payroll team whether your company runs a salary sacrifice scheme. Not all do, but it costs employers nothing (they actually save money), so more are offering it each year.
Watch out for the downsides
Salary sacrifice is not free money. Your contractual salary drops, and that has knock-on effects:
- Statutory pay — Maternity, paternity, and sick pay are calculated on your reduced salary. If the sacrifice brings your earnings close to the lower earnings limit, check the numbers carefully.
- Mortgage applications — Lenders look at your contractual salary. A lower figure could reduce what you can borrow.
- National Minimum Wage — Your cash pay after sacrifice cannot fall below the legal minimum. Your employer should block this automatically.
- Flexibility — Most schemes only let you change contribution levels at set points (annually, or on a life event like having a child). Check before you commit.
How to set it up
- Confirm your employer offers salary sacrifice for pensions.
- Decide how much to sacrifice per month. Use our salary calculator to see the take-home impact at different amounts.
- Sign the contract variation your employer provides.
- Check your next payslip — your gross pay should be lower, your pension contribution higher, and your tax/NI deductions reduced.
If you are unsure whether the trade-off works for you, run the numbers both ways on our calculator and compare. The tax and NI savings are real, but so is the lower headline salary.