Salary Sacrifice Pensions Explained (2026/27)
Salary sacrifice is the most tax-efficient way most employees can contribute to a pension — yet many people don't realise their scheme uses it, or how much more it saves compared with the alternative. This guide explains the mechanics and the numbers.
The Take-Home Pay Calculator assumes salary sacrifice by default for pension contributions — this page explains why that matters.
Contents
How salary sacrifice actually works
Under a salary sacrifice arrangement, you don't actually "contribute" part of your salary to a pension in the conventional sense. Instead, you formally agree to reduce your contractual salary by the amount you want to go into your pension, and your employer pays that amount directly into your pension pot instead.
Because your contractual salary is genuinely lower, that portion of income:
- Is never subject to Income Tax (since it was never paid to you as salary).
- Is never subject to employee National Insurance (same reason).
- Often isn't subject to employer National Insurance either — and some employers pass some or all of that saving back into your pension as an extra contribution.
This is the key mechanical difference from simply "putting money into a pension" — it changes what counts as your salary in the first place, rather than giving you tax relief on money you've already received and then paid in.
Salary sacrifice vs relief-at-source
Relief-at-source is the more common default in personal and some workplace pensions: you contribute from your take-home (post-tax) pay, and the pension provider claims back basic-rate tax (20%) from HMRC to add to your pot. Higher and additional-rate taxpayers must then separately claim back the extra relief via Self Assessment or by contacting HMRC — it isn't automatic.
| Salary sacrifice | Relief-at-source | |
|---|---|---|
| Income Tax relief | Automatic, at your full marginal rate | Basic rate automatic; higher/additional rate needs claiming separately |
| National Insurance | Saved on the sacrificed amount (employee, and often employer) | Not saved — NI is charged on your income before the pension contribution is made |
| Effect on payslip | Contractual salary reduced | Salary unchanged; contribution taken from net pay |
| Effect on other thresholds (e.g. Personal Allowance taper) | Reduces "adjusted net income," so it can help | Also reduces adjusted net income, but the immediate NI saving is missing |
The National Insurance saving is the crucial difference — it's not available at all under relief-at-source, and it's the reason salary sacrifice usually comes out ahead even for basic-rate taxpayers.
Worked example
Someone earning £40,000, contributing 5% of salary (£2,000/year) to a pension:
Salary sacrifice:
| Item | Amount |
|---|---|
| Reduced salary for tax/NI purposes | £38,000 |
| Income Tax saved | £400 (20% of £2,000) |
| National Insurance saved | £160 (8% of £2,000) |
| Total saving | £560 |
| Real cost of £2,000 in the pension | £1,440 |
Relief-at-source (equivalent net contribution):
| Item | Amount |
|---|---|
| Take-home pay before pension | £32,320 |
| Net amount paid into pension | £1,440 |
| Basic-rate relief added by provider (20%) | £360 |
| Amount landing in the pension | £1,800 |
| Real cost from take-home pay | £1,440 |
For the same £1,440 reduction in take-home pay, salary sacrifice puts £2,000 into the pension, while relief-at-source (for a basic-rate taxpayer, without separately claiming anything) puts in £1,800 — a £200 difference purely from the National Insurance saving, on identical take-home pay impact.
Why it's worth more the higher you earn
If part of the sacrificed amount would otherwise have been taxed at 40% (i.e. you earn over £50,270), the Income Tax saving alone jumps to 40%, and relief-at-source would require actively claiming the extra relief via Self Assessment rather than receiving it automatically. Sacrifice above £100,000 is particularly valuable, since it can also claw back Personal Allowance lost to the taper — see the £100,000 after tax breakdown and the Income Tax Explained guide's 60% tax trap section for worked examples of that effect.
Effects beyond the pension pot
Because salary sacrifice reduces your actual contractual salary, it can affect other calculations tied to your income:
- Personal Allowance taper — reduces "adjusted net income," which can restore lost allowance if you're earning over £100,000.
- High Income Child Benefit Charge — similarly based on adjusted net income, so sacrifice can reduce or eliminate the charge.
- Student loan repayments — sacrificed salary isn't counted as income for student loan repayment purposes either, reducing repayments alongside tax and NI.
- Statutory pay and mortgage affordability — a lower contractual salary can, in some cases, affect Statutory Maternity/Paternity Pay calculations or how lenders assess income for a mortgage, since some methods use contractual salary rather than gross pay before sacrifice. Worth checking with your employer or lender if either applies to you.
Downsides to be aware of
- Reduces your contractual salary, which can affect income-based calculations elsewhere (see above) — not always to your advantage.
- Below National Minimum Wage risk — HMRC rules prevent salary sacrifice from reducing your pay below the National Minimum/Living Wage, so lower earners may be capped in how much they can sacrifice.
- Less flexible — because you're formally changing your contract, some employers require a minimum commitment period before you can change the sacrificed amount again.
- Mortgage applications — some lenders use your contractual (post-sacrifice) salary rather than gross salary, which can occasionally affect how much they'll lend, though many now account for this correctly.
FAQ
Is salary sacrifice always better than relief-at-source?
Almost always, in pure take-home-pay-per-pound-in-pension terms, because of the National Insurance saving — but check the downsides above, particularly around mortgage applications and Statutory Pay calculations, if either is relevant to you.
Does salary sacrifice affect my State Pension?
Only if it reduces your income below the Lower Earnings Limit (£6,708/year for 2026/27), which would affect whether that year counts as a qualifying year for NI purposes. For most earners, sacrificing a reasonable percentage of a full-time salary won't bring you anywhere near this threshold.
Can my employer refuse to offer salary sacrifice?
Yes — it requires setting up the arrangement and adjusting contracts, so not every employer offers it. Ask your HR or payroll team whether your workplace pension scheme uses salary sacrifice or relief-at-source.
How do I know if my pension is already salary sacrifice?
Check your payslip — if your pension contribution appears as a reduction to your gross/taxable pay rather than a separate deduction from net pay, it's salary sacrifice. Your HR or payroll team can confirm directly.
Does salary sacrifice affect my employer's National Insurance too?
Yes — employers also stop paying their 15% NI on the sacrificed amount, which is why some employers pass some or all of that additional saving back into your pension as a top-up contribution. Worth asking whether yours does.
More guides
This page is for general information only and does not constitute financial advice. Figures are correct for the 2026/27 tax year. For advice on your specific pension arrangement, consult your employer's scheme documentation or a qualified financial adviser.