Salary Sacrifice Explained: How to Pay Less Tax and Build a Bigger Pension

For a basic-rate taxpayer, every £100 sacrificed into a pension costs just £72 in take-home pay. For a higher-rate taxpayer, it costs £58. For someone in the £100k–£125k Personal Allowance taper zone, it costs just £40.

Salary sacrifice is one of the most powerful — and most underused — tax tools available to UK employees. This guide explains exactly how it works, with real numbers.

What is salary sacrifice?

Salary sacrifice is an agreement between you and your employer to reduce your gross salary in exchange for a non-cash benefit — most commonly pension contributions.

Instead of earning £45,000 and paying pension contributions from your net pay, you agree to earn £42,000 and have £3,000 paid directly into your pension by your employer.

The result? You pay tax and National Insurance on £42,000 instead of £45,000.

Salary sacrifice is not the same as a pay cut. Your total compensation stays the same — you simply receive part of it as pension contributions instead of cash.

How much can you actually save?

Here is a real example for someone earning £45,000 sacrificing an extra £200/month (£2,400/year):

Instead of costing £2,400, the contribution only costs £1,728 — because the government effectively subsidises £672 of it through tax and NI relief.

Why salary sacrifice beats paying into a pension normally

There are two ways to contribute to a pension:

1. Salary sacrifice — reduces gross pay before tax and NI
2. Relief at source — you pay from net pay, HMRC adds 20% back

Salary sacrifice saves both income tax AND National Insurance. Relief at source only saves income tax. For most employees, salary sacrifice is more efficient.

The employer NI bonus

Here is something most employees don't know: your employer also saves NI when you sacrifice salary.

Employers pay 13.8% NI on your earnings. When you sacrifice £2,400, your employer saves:

£2,400 × 13.8% = £331

Many employers pass this saving back into your pension. It is worth asking your HR team.

Who benefits most from salary sacrifice?

Higher earners benefit most — especially those earning between £100,000 and £125,140 where the effective marginal tax rate is 60% due to the Personal Allowance taper. See our £100k tax trap guide for the full explanation.

Child Benefit and the £60,000 trap

If your Adjusted Net Income exceeds £60,000, you start repaying Child Benefit through the High Income Child Benefit Charge (HICBC).

• Between £60,000–£80,000: you repay 1% for every £200 above £60,000
• Above £80,000: you repay 100% of Child Benefit

Salary sacrifice reduces your Adjusted Net Income — so it can eliminate this charge entirely. A parent earning £65,000 with 2 children receives £2,251/year in Child Benefit but repays over £500 via HICBC. Sacrificing £5,000/year brings their ANI to £60,000 — saving the full charge on top of the usual tax and NI savings.

Read our full Child Benefit tax charge guide for worked examples.

The Annual Allowance limit

You can contribute up to £60,000 per year into your pension (or 100% of your earnings, whichever is lower). This includes both employee and employer contributions.

Most people are nowhere near this limit — but it is worth knowing if you are making large additional contributions.

How to set up salary sacrifice

1. Check your employer offers it — most do, but not all
2. Contact HR or payroll — ask to increase your salary sacrifice pension contribution
3. Agree a new amount — this changes your employment contract
4. See it on your payslip — your gross pay will be lower, and so will your tax and NI

Salary sacrifice can affect mortgage affordability assessments, as lenders look at gross salary. Check with your mortgage adviser before making large changes.

What this means for you

The numbers above are not theoretical. A basic-rate taxpayer who increases their pension sacrifice by £200/month saves £672/year in tax and NI — money that would otherwise go to HMRC. Over 20 years, with investment growth, that difference in pension contributions compounds significantly.

For a complete breakdown of all salary sacrifice options — including EV leasing, cycle-to-work, and step-by-step setup — see our complete salary sacrifice guide for 2026/27.

Try the TaxCal UK calculator to estimate your take-home pay.

Summary

• Salary sacrifice reduces your gross pay before tax and NI
• Every £100 sacrificed costs a basic rate taxpayer just £72 in take-home pay
• Higher rate taxpayers save even more — as little as £58 per £100
• Employer NI savings (13.8%) may be passed back to you
• It can eliminate the Child Benefit charge for incomes between £60k–£80k

FAQ

Is salary sacrifice the same as a pay cut?

No. Your total compensation stays the same — you receive part of it as a pension contribution rather than cash. Your gross pay on the payslip is lower, but your overall package is unchanged.

Does salary sacrifice affect my mortgage?

Potentially. Some lenders use post-sacrifice gross salary for affordability. Check with your mortgage adviser before making large changes.

Can I sacrifice salary into a SIPP?

Only if your employer supports it. Most workplace salary sacrifice schemes use the employer's chosen pension provider. You can contribute to a SIPP separately via relief at source.

What happens to my pension if I leave my job?

Your pension pot stays with the provider. You can transfer it to your new employer's scheme or a personal pension.