Salary Sacrifice for Pension: How It Works & How Much You Save
Salary sacrifice lets you boost your pension while paying less tax and NI — here's exactly how it works with real examples.
What Is Salary Sacrifice?
Salary sacrifice (also known as salary exchange) is an arrangement where you agree to give up a portion of your gross salary in exchange for a non-cash benefit from your employer — most commonly an employer pension contribution. Because your contractual salary is reduced, you pay less income tax and less National Insurance on the lower figure. Your employer also pays less employer National Insurance — a saving they can optionally pass on to boost your pension further.
Salary sacrifice is not a loophole: it is explicitly approved by HMRC and widely used by employers across the UK. It is simply the most tax-efficient way to fund a pension when your employer offers it.
How It Reduces Your Tax and NI
When you contribute to a pension via a traditional personal contribution, you contribute from net pay and HMRC adds basic rate tax relief directly to your pot. With salary sacrifice, the contribution comes from your gross salary before any tax or NI is calculated — meaning you save income tax at your marginal rate AND National Insurance at 8% (or 2% above £50,270). This is more efficient than the relief-at-source approach.
Worked Example: £45,000 Salary, 5% Sacrifice
| Item | Without Sacrifice | With 5% Sacrifice |
|---|---|---|
| Gross salary | £45,000 | £42,750 |
| Sacrifice amount | £0 | £2,250 |
| Income tax (est.) | £6,486 | £6,036 |
| Employee NI (8%) | £2,594 | £2,414 |
| Net take-home | £35,920 | £34,300 |
| Pension contribution | £0 | £2,250 |
| Net cost of contribution | — | £1,620 (£2,250 − £630 tax/NI saved) |
The £2,250 pension contribution effectively costs just £1,620 in reduced take-home pay — a saving of £630 per year, or £52.50 per month. The tax and NI saved represent a 28% discount on the pension contribution.
The Employer NI Saving — and How to Get It
Your employer saves 13.8% employer National Insurance on the sacrificed amount. On a £2,250 sacrifice, that is £310.50 the employer no longer pays to HMRC. Many forward-thinking employers pass this saving on to the employee's pension pot — adding £310.50 to your pension at no cost to you. Always ask HR whether your employer passes on their NI saving, as the rules vary by employer.
Limits and Things to Watch
Impact on State Pension
Your salary sacrifice reduces your contractual salary. If your sacrificed salary falls below the Lower Earnings Limit (£6,396 in 2025/26), you may lose NI credits that count towards your State Pension. Ensure your post-sacrifice salary remains above this threshold.
Impact on Mortgage Applications
Mortgage lenders assess affordability based on your contracted salary. If salary sacrifice significantly reduces your stated salary on payslips and P60, it may reduce your maximum mortgage offer. Check with your lender or broker before setting up a large sacrifice if you plan to apply for a mortgage soon.
Impact on Other Benefits
Some employment benefits — including statutory maternity/paternity pay, life insurance cover multiples, and death-in-service benefits — may be calculated on contracted salary. A lower contracted salary can reduce these benefits. Review your employment contract carefully before committing to a sacrifice arrangement.
How to Set It Up
Salary sacrifice requires your employer to offer it — you cannot set it up unilaterally. Speak to your HR or payroll department and ask whether the company operates a salary sacrifice pension arrangement. If they do, you typically complete a form specifying your sacrifice amount (as a fixed sum or percentage), and the arrangement is formalised via a variation to your employment contract. Changes usually take effect from the next pay period.
If your employer does not offer salary sacrifice, personal pension contributions (relief at source) are the next best option — you still get full income tax relief, just not the NI saving.
Use our Salary After Tax Calculator to see your take-home with and without sacrifice →