Salary Sacrifice and Pension Contributions

Salary sacrifice is quietly one of the most tax-efficient ways to pay into a pension, yet a surprising number of eligible employees have never been offered it, or have never asked. Rather than paying your pension contribution out of your take-home salary and relying on tax relief to top it up afterwards, you agree to give up part of your salary before it is paid, in exchange for your employer paying an equivalent, or often enhanced, amount directly into your pension instead. Because that sacrificed amount never counts as salary in the first place, it escapes not just income tax but National Insurance too — a saving that a standard pension contribution, however it is relieved, cannot match. This guide explains exactly how the mechanics work, what the saving looks like in pounds and pence, and the practical downsides worth weighing up before agreeing to it.

How salary sacrifice actually works

In a typical salary sacrifice arrangement, you agree with your employer to reduce your contractual salary by a set amount, and in exchange your employer increases its own pension contribution by that same amount (or sometimes more, if the employer chooses to share some of its own saving with you, as discussed below). The net effect on your pension is often identical to what you would have contributed through ordinary payroll deduction — the same amount ends up in your pot — but because the money is reclassified as an employer pension contribution rather than personal salary, it is never subject to income tax or National Insurance at all, for either you or your employer.

This is a fundamentally different mechanism to the tax relief methods described in our guide on how pension tax relief works. Relief at source and net pay arrangements both still involve you technically earning the money and then either paying tax on it and reclaiming relief, or having it deducted before tax is calculated. Salary sacrifice sidesteps income tax relief altogether, because the money is never "yours" as salary to begin with — it goes straight from your employer into your pension as an employer contribution, which is why it also escapes National Insurance, something ordinary pension tax relief never touches.

Why it saves National Insurance for both employee and employer

National Insurance is charged on earnings, not on employer pension contributions, so any amount converted from salary into an employer pension contribution through salary sacrifice reduces the earnings figure that National Insurance is calculated on. For most employees, this means saving National Insurance at the standard employee rate on the sacrificed amount. Employers benefit too: they currently pay a substantial employer National Insurance rate on employee earnings above a threshold, and every pound moved from salary into pension via salary sacrifice reduces the wage bill that this is charged on, saving the employer money as well as the employee.

This dual saving is exactly why many employers actively promote salary sacrifice schemes: it is one of the few workplace benefits that can genuinely cost the employer less overall while leaving the employee no worse off, and often better off, than a standard payroll deduction arrangement.

Worked example: the National Insurance saving in pounds

Consider an employee earning £35,000 a year who currently contributes 5% of qualifying earnings to their pension (the typical employee share under auto-enrolment, including tax relief), and is deciding whether to move this to a salary sacrifice arrangement instead. The table below compares the two approaches for a £1,450 annual pension contribution.

In this example, the employee saves approximately £116 a year in National Insurance simply by routing the same contribution through salary sacrifice rather than a standard payroll deduction, at no extra cost to themselves. The employer, meanwhile, saves employer National Insurance on the same £1,450 — typically a saving of well over £200 a year at current employer National Insurance rates — money that costs the employer nothing extra to give, since it is simply avoided tax rather than an additional benefit they are funding themselves.

Why some employers pass their own saving back to you

Because the employer makes a genuine National Insurance saving on every pound sacrificed, some employers choose to pass some or all of that saving back into the employee's pension as an extra "bonus" contribution, on top of the amount originally sacrificed. This is not a legal requirement — an employer is entitled to keep its own National Insurance saving for itself — but many employers do this, at least in part, as a way of making salary sacrifice a more attractive benefit and encouraging take-up. If your employer offers salary sacrifice, it is always worth specifically asking whether they pass back any of their own employer National Insurance saving, since this can meaningfully increase the amount that actually ends up in your pension compared to a scheme where the employer simply keeps the saving for itself.

Potential downsides to weigh up

Salary sacrifice is not free of trade-offs, and it is worth understanding these before signing up. Because your contractual salary is genuinely reduced, rather than simply having a deduction taken from it, this lower salary figure can affect other calculations that use your salary as a reference point. Mortgage lenders generally assess affordability based on your contractual salary, so a salary sacrifice arrangement can, in some cases, slightly reduce the amount a lender is willing to offer, even though your actual take-home pay may be very similar once the National Insurance saving is accounted for — it is worth mentioning any salary sacrifice arrangement to a mortgage broker or lender so they can use the correct figures in their assessment.

Statutory benefits calculated from your average earnings, such as Statutory Maternity Pay, Statutory Paternity Pay, and Statutory Sick Pay, are also based on your actual earnings during a specific reference period, so a lower contractual salary from salary sacrifice can, in principle, reduce these payments if the sacrifice is in place during the relevant assessment period. Many employers build in specific protections around this — for example, automatically suspending salary sacrifice during maternity leave, or calculating statutory payments as if sacrifice had not been in place — but this varies by employer, so anyone planning a family, or anticipating a period of illness, should check their own employer's specific policy on this point before relying on salary sacrifice remaining unaffected.

More generally, a reduced contractual salary can also affect anything else calculated as a multiple or percentage of salary, such as life assurance cover provided by an employer (often set at a multiple of salary), redundancy pay calculations, or the maximum amount you are able to borrow through certain employer loan schemes. None of these effects are usually large, but they are worth checking individually against your own circumstances, particularly if you are planning a mortgage application, a period of leave, or are relying on employer-provided death-in-service cover as part of your financial planning.

Who might not be able to use salary sacrifice

Not everyone is able to sacrifice as much salary as they might like, because your resulting salary cannot be reduced below the National Minimum Wage or National Living Wage rate for your age group — an employer is legally required to check this before agreeing to any sacrifice arrangement, and will typically cap how much you can sacrifice if your salary is relatively close to the relevant minimum. This tends to affect lower earners disproportionately, since a smaller salary leaves less headroom above the wage floor to sacrifice in the first place, which is one of the reasons salary sacrifice, while available in principle to almost anyone, tends to deliver the largest practical benefit to middle and higher earners with more salary to work with. Anyone close to the minimum wage threshold should ask their employer specifically how much they are able to sacrifice before assuming the full amount they would like to contribute is available through this route.

It is also worth noting that some employers only offer salary sacrifice to staff above a certain length of service, or exclude certain categories of worker such as agency staff or those on zero-hours contracts, so it is worth checking eligibility criteria specific to your own employment status rather than assuming it applies universally across a workforce.

Interaction with other salary sacrifice benefits

Pension salary sacrifice is often just one of several salary sacrifice benefits an employer might offer, alongside things like cycle-to-work schemes, electric car leasing, or childcare support. Because each of these reduces your contractual salary in the same way, sacrificing into several schemes at once can add up to a substantial total reduction in salary, which makes it even more important to check the cumulative effect on the National Minimum Wage floor, mortgage affordability, and statutory pay calculations described above. If you are considering combining pension salary sacrifice with another scheme, it is worth asking payroll to confirm your resulting salary figure after all sacrifices are applied, rather than assessing each scheme in isolation.

Is salary sacrifice something HMRC allows?

Yes — salary sacrifice for pension contributions is a well-established and entirely legitimate arrangement recognised by HMRC, provided it is set up correctly as a genuine variation to your employment contract, rather than simply a label applied to what is really still just a normal payroll deduction. This generally means your contract of employment (or a side letter) needs to be updated to reflect the reduced salary, and the change needs to be treated as a real change to your pay and benefits package going forward, not merely a re-badging of your existing pension deduction on a payslip. Employers running properly constituted salary sacrifice schemes, following HMRC's published guidance on the subject, are on solid ground, which is why the arrangement has become increasingly common across UK employers of all sizes in recent years.

How to ask your employer about setting it up

If your employer does not currently offer salary sacrifice, or you are unsure whether they do, the most direct route is simply to ask HR or payroll whether a salary sacrifice pension scheme is available, and if not, whether they would consider introducing one. Employers of all sizes can typically operate salary sacrifice for pension contributions with relatively little administrative complexity through their existing payroll software, and given that it saves the employer money as well as the employee, it is often a request that is well received, even at smaller employers who may not have previously considered it. If your employer already offers salary sacrifice, worthwhile questions to ask include whether they pass back any of their own National Insurance saving, whether the arrangement is automatically suspended during maternity, paternity, or long-term sick leave, and whether there is a minimum salary you must remain above (often linked to the National Minimum Wage) that could limit how much you are able to sacrifice.

Comparing salary sacrifice against a standard contribution

Quick recap

Salary sacrifice converts part of your salary into an employer pension contribution, saving both employee and employer National Insurance on the sacrificed amount, on top of the usual income tax benefits of pension saving. Some employers pass back part of their own saving as an extra contribution, making it even more valuable. The main things to check before agreeing are whether it might affect a mortgage application, statutory maternity, paternity, or sick pay, or any other benefit calculated from your salary — and your employer's HR team should be able to answer these questions specific to their own scheme.