Salary sacrifice is one of the most tax-efficient arrangements available to UK employees — yet a significant proportion of workers either don't use it or don't fully understand how much it's saving them. This guide explains exactly how it works, using real 2026/27 tax year numbers.
What is salary sacrifice?
Salary sacrifice (sometimes called "salary exchange") is a formal agreement between you and your employer. You agree to reduce your contractual gross salary by a set amount, and your employer agrees to pay that amount directly into your chosen scheme — most commonly your workplace pension.
The key distinction from other methods: your official gross pay is reduced before tax and National Insurance are calculated. This means you save both income tax and employee NI on the sacrificed amount, not just income tax.
How does salary sacrifice save tax and NI?
Here's a concrete example. You earn £40,000 per year and contribute £200/month to your pension:
| Scenario | Monthly gross | Monthly tax paid | Monthly NI paid | Monthly take-home |
|---|---|---|---|---|
| No pension | £3,333 | £373 | £175 | £2,785 |
| Relief at Source pension | £3,333 | £333 | £175 | £2,625 (£160 real cost) |
| Salary Sacrifice pension | £3,133 | £333 | £159 | £2,641 (£144 real cost) |
With salary sacrifice, your £200/month pension contribution only costs you £144 out of pocket — a saving of £56/month or £672/year compared to not saving into a pension at all.
Who benefits most from salary sacrifice?
The more tax and NI you pay, the more you save with salary sacrifice. Higher rate taxpayers (income above £50,270) save 42p per £1 sacrificed — the biggest available benefit for employees. Even basic rate taxpayers save 28p per £1.
If you're close to the £100,000 income threshold where the personal allowance begins tapering, salary sacrifice can be extremely powerful: reducing your gross pay below £100,000 can restore your full personal allowance, effectively creating a 60% marginal tax rate saving on the amount in that band.
What can I sacrifice salary into?
The most common salary sacrifice schemes are:
- Pension contributions — the most widely available and most tax-efficient. Any workplace pension can typically be set up as salary sacrifice.
- Cycle to Work — buy a bike and safety equipment tax-free, typically up to £3,000 (or more for electric bikes). You sacrifice a monthly amount over 12 months.
- Electric Vehicle leasing (ULEV) — lease an electric car through your employer. The Benefit in Kind (BiK) rate for fully electric vehicles is just 2% for 2026/27, making this exceptionally tax-efficient for higher earners.
- Childcare vouchers — this scheme is now closed to new entrants (replaced by Tax-Free Childcare), but existing members can continue.
Does salary sacrifice affect my state pension?
This is the most commonly cited concern. The answer is: it can, but in practice the impact is usually very small and is outweighed by the immediate tax saving.
Your state pension entitlement depends on having enough qualifying years of NI contributions. If your NI-able earnings drop below the Lower Earnings Limit (£6,396 in 2026/27), that year won't count as a qualifying year. For most full-time workers, even with significant salary sacrifice, earnings stay well above this threshold.
Does salary sacrifice affect my mortgage?
Potentially yes, and this is worth understanding before agreeing to a large sacrifice. Your official gross salary — what's on your payslip and in your employment reference — will be lower than your pre-sacrifice salary. Most lenders use gross income to determine maximum mortgage lending.
Some lenders are aware of salary sacrifice and will "add back" the sacrificed amount when assessing affordability. Ask your mortgage broker specifically about this before increasing your sacrifice amount.
Can my employer refuse salary sacrifice?
Yes. Salary sacrifice requires an amendment to your employment contract, so it requires employer agreement. However, it's in your employer's interest to offer it for pension contributions — because they also save employer NI (13.8%) on the sacrificed amount. A £200/month pension sacrifice saves your employer £27.60/month per employee. Many forward-thinking employers pass some or all of this saving back to employees as an additional pension contribution.
How to set up salary sacrifice
If your employer offers it:
- Contact your HR or payroll team and request to opt in to salary sacrifice for your pension (or other scheme).
- They will issue a salary sacrifice agreement — a document showing the new lower gross salary.
- Your next payslip will show the lower gross, with pension contributions appearing separately.
- Your tax code doesn't change — but your taxable gross will be lower.
How to check if you're already on salary sacrifice
Look at your payslip. If you can see a pension deduction listed above or before the income tax calculation — or if there's a line for "pension sacrifice" or "salary exchange" that reduces your gross pay — you're already on salary sacrifice. You can also check your employment contract or ask your payroll team to confirm.
For official HMRC guidance on salary sacrifice, see the GOV.UK salary sacrifice guidance. To understand how your pension deductions appear on your payslip, read our pension deduction explainer.