Salary Sacrifice vs Relief at Source UK (2026/27)
Salary sacrifice, net pay and relief at source compared on a £4,000 pension contribution across four salaries. Sacrifice wins, and by how much.
UK workplace pensions deliver tax relief through one of three mechanisms: salary sacrifice, net pay arrangement, or relief at source. They produce different take-home pay, different cash-flow timing, and - in the case of salary sacrifice - different total relief, because only SS escapes National Insurance as well as Income Tax. This page compares all three on an identical £4,000 gross contribution across four salary bands, with figures computed by the same engine that drives the salary calculator.
The three UK pension tax-relief methods
- Salary sacrifice (SS) - the employee contractually gives up part of their gross salary in exchange for the employer making a corresponding pension contribution. The sacrificed amount never reaches payroll as taxable income, so it escapes both Income Tax (20% / 40% / 45%) and employee National Insurance (8% on the main band, 2% above the Upper Earnings Limit). The employer also saves their 15% Class 1 Secondary NI on the sacrificed amount and frequently rebates some or all of that saving into the employee's pension pot.
- Net pay arrangement (NPA) - the employee contribution is deducted from gross pay before Income Tax is calculated, but after National Insurance is calculated. Saves IT at the marginal rate, does not save NI. Standard for most occupational defined-benefit schemes (NHS, Teachers', LGPS, USS, Civil Service) and many large DC master-trusts. Relief is automatic and immediate - no claim required.
- Relief at source (RAS) - the employee contribution is deducted from net pay (post-Income-Tax, post-NI). The pension provider then claims 20% basic-rate relief directly from HMRC and adds it to the pot - so a £3,200 net contribution becomes £4,000 gross. Higher-rate (40%) and additional-rate (45%) taxpayers must reclaim the extra 20% / 25% through Self Assessment or by writing to HMRC. The one structural advantage: non-taxpayers still get the 20% top-up, on contributions of up to 80% of their earnings (net), or £2,880 net (£3,600 gross) if they have no earnings.
Worked example: £4,000 pension contribution at each salary band
Identical £4,000 gross-equivalent contribution into a UK registered pension. All figures computed by the salary engine on 2026/27 HMRC rates, England rest-of-UK bands. "Net cost" is the actual reduction in take-home pay (after any SA refund); "Effective relief" is the saved fraction of the £4,000 gross contribution.
| Salary | Method | Net cost | Pension | Relief |
|---|---|---|---|---|
| £40,000 Basic rate (20% IT, 8% NI) | Salary sacrifice | £2,880 | £4,000 | 28.0% |
| Net pay arrangement | £3,200 | £4,000 | 20.0% | |
| Relief at source | £3,200 | £4,000 | 20.0% | |
| £60,000 Higher rate (40% IT, 2% NI) | Salary sacrifice | £2,320 | £4,000 | 42.0% |
| Net pay arrangement | £2,400 | £4,000 | 40.0% | |
| Relief at source | £2,400 | £4,000 | 40.0% | |
| £100,000 Higher rate, just below PA taper | Salary sacrifice | £2,320 | £4,000 | 42.0% |
| Net pay arrangement | £2,400 | £4,000 | 40.0% | |
| Relief at source | £2,400 | £4,000 | 40.0% | |
| £130,000 Additional rate (45% IT, 2% NI) | Salary sacrifice | £2,120 | £4,000 | 47.0% |
| Net pay arrangement | £2,200 | £4,000 | 45.0% | |
| Relief at source | £2,200 | £4,000 | 45.0% |
Note: NPA and RAS produce the same total relief at every salary band shown because both eventually deliver IT relief at the marginal rate. They differ in cash-flow timing - NPA relief is automatic and immediate at payroll; RAS relief above the basic rate has to be claimed back through Self Assessment, which can take 6 - 18 months.
Why salary sacrifice wins (almost always)
SS is structurally more tax-efficient than the other two because it escapes employee National Insurance as well as Income Tax. The gap ranges from 8 percentage points at basic rate to ~2 percentage points above the Upper Earnings Limit. On a single £4,000 contribution:
- At £40,000 gross, SS net cost is £2,880, NPA/RAS net cost is £3,200 - SS keeps an extra £320 in your pocket (8.0 pp more relief).
- At £60,000 gross, SS net cost is £2,320, NPA/RAS net cost is £2,400 - SS keeps an extra £80 in your pocket (2.0 pp more relief).
- At £100,000 gross, SS net cost is £2,320, NPA/RAS net cost is £2,400 - SS keeps an extra £80 in your pocket (2.0 pp more relief).
- At £130,000 gross, SS net cost is £2,120, NPA/RAS net cost is £2,200 - SS keeps an extra £80 in your pocket (2.0 pp more relief).
On top of that, many employers rebate part or all of their 15% Class 1 Secondary NI saving into the employee's pension pot - a "100% NI rebate" scheme adds an extra £600 to a £4,000 sacrifice pot, lifting the effective relief well above the figures shown in the table. Always ask payroll whether your scheme includes an employer NI rebate - it is one of the highest-return uplifts available in UK employment compensation.
The NI advantage is capped from April 2029. HMRC: "From April 2029, only the first £2,000 of employee pension contributions through salary sacrifice each year will be exempt from NICs", with employee and employer NI charged on the excess (HMRC policy paper, 26 November 2025; enabling legislation, the National Insurance Contributions (Employer Pensions Contributions) Act 2026). On the £4,000 contribution in the table, £2,000 would then carry NI, so the SS advantage over the long run is smaller than the 2026/27 figures above. Income Tax relief is not affected.
When RAS still makes sense
RAS is the right method (or the only available method) in several common situations:
- Low earners below the Personal Allowance - someone earning £10,000 a year pays no Income Tax, so a net pay arrangement has no tax to relieve at the time. RAS adds the 20% basic-rate top-up straight into the pot. Since 6 April 2024 HMRC closes most of that gap: net pay savers "whose total taxable income is below the personal allowance" are paid a basic-rate top-up after the end of the tax year, starting with 2024/25 (FA 2004 s.193A; announced in the Autumn Budget 2021, per HMRC's policy paper). The difference that remains is timing, and that the top-up is paid to you rather than into the pension.
- Non-employer SIPP contributions - personal pensions and SIPPs (Vanguard, AJ Bell, Hargreaves Lansdown, etc.) run exclusively on RAS. If you are contributing from after-tax savings rather than payroll, RAS is the only mechanism available to you.
- Employer does not offer salary sacrifice - many small-firm workplace pensions and some master-trusts only offer RAS. There is no way to manufacture salary sacrifice unilaterally; if it is not on offer, RAS (or NPA, depending on the scheme) is what you have.
- You need the gross salary figure preserved - because RAS does not reduce contractual gross pay, it leaves mortgage affordability, Statutory Maternity Pay and life cover all calculated on the full pre-contribution salary. SS can reduce those. It affects your State Pension only if it takes your earnings below the NI Lower Earnings Limit (£6,708 a year in 2026/27). Above that limit, NI is "treated as having been paid to protect your National Insurance record" even where you pay none (gov.uk), so a smaller NI bill does not cost you a qualifying year.
The £60,000 Annual Allowance applies to all three
Regardless of which relief method delivers the contribution, every pound paid into a UK registered pension counts toward the Annual Allowance - £60,000 of gross contributions per tax year in 2026/27, with a three-year carry-forward of any unused allowance from the previous three tax years. The allowance tapers down to a floor of £10,000 when threshold income is over £200,000 and adjusted income exceeds £260,000: it falls by £1 for every £2 of adjusted income above £260,000. If threshold income is £200,000 or less there is no taper, whatever the adjusted income (gov.uk). The taper cannot be sidestepped by using salary sacrifice - employer contributions, including sacrificed salary, count in adjusted income.
Exceeding the annual allowance creates an Annual Allowance Charge: the excess is added to taxable income and taxed at your marginal rate, effectively clawing back the relief you would otherwise have received. The charge can sometimes be paid out of the pension itself ("Scheme Pays") rather than from cash, but the practical limit is the same regardless of contribution method.
Related
Frequently asked questions
Why does my employer use net pay arrangement instead of salary sacrifice?
Most large occupational pension schemes (NHS, USS, LGPS, Civil Service, BT) run on a net pay arrangement because that is how they have been structured for decades and changing the basis is administratively complex. Salary sacrifice requires the employer to formally vary the employment contract for each participant and to recalculate gross pay for every other purpose (mortgage references, P60s, statutory payments). Many private-sector employers do now offer SS, but it usually has to be opted into rather than being the default.
Can I switch from relief at source to salary sacrifice?
Only if your employer operates an SS scheme. If they do, the switch is a contractual variation - your gross salary is reduced, the employer pays the corresponding amount directly into the pension, and you stop making employee contributions out of net pay. HMRC sets no minimum commitment period: what matters is that your contract is actually changed each time you opt in or out, and HMRC's guidance allows opting in or out on a lifestyle change such as marriage or a new baby. If your employer does not offer SS at all (common in small firms and most public sector roles), you cannot switch unilaterally - the pension scheme is what it is.
How do I claim the extra 20% relief on RAS as a higher-rate taxpayer?
Through Self Assessment if you already file one, or by writing to HMRC (you can do it through your Personal Tax Account at gov.uk) with the gross contribution amount and a copy of the pension statement. HMRC then either issues a refund, adjusts your tax code so you take home more during the year, or both. For higher-rate taxpayers the extra reclaim is 20% of the gross contribution (so £800 on a £4,000 contribution); for additional-rate taxpayers it is 25% (£1,000). Many higher-rate RAS savers forget to claim and lose out on years of relief - the time limit is 4 years.
Does salary sacrifice affect Statutory Maternity Pay or my mortgage application?
Yes - this is the main practical downside. SMP is calculated on the lower post-sacrifice salary (the first six weeks at 90% of average weekly earnings can be materially lower), and most mortgage lenders use post-sacrifice gross as the affordability figure (some specialist lenders consider the pension contribution as discretionary income, but they are not the default). Net pay arrangement and relief at source do not have this side effect because gross salary is unchanged. If you are planning to take maternity leave or apply for a mortgage within 12 - 18 months, it is worth pausing or reducing salary sacrifice contributions.
Does the £260,000 adjusted income annual allowance taper apply to all three methods?
Yes - the £60,000 annual allowance, and the taper that reduces it by £1 for every £2 of adjusted income over £260,000 (down to £10,000), apply equally to salary sacrifice, net pay and relief at source contributions. The taper applies only if your threshold income is also over £200,000. Adjusted income is your net income plus your own pension contributions and your employer's contributions for you, so salary-sacrificed amounts count in it and SS does not let you sidestep the taper.
What happens to my contributions if I leave my employer mid-year?
Salary sacrifice and net pay contributions stop the day employment ends - they only exist while you are on payroll. Relief at source contributions through a personal pension or Self-Invested Personal Pension (SIPP) carry on regardless of employment status, and you can keep contributing from new earnings or savings. All three pots stay invested under your name and can be transferred to a new employer scheme or consolidated into a SIPP. The basic-rate top-up on RAS is available even if you have zero earnings in the year, up to £3,600 gross (£2,880 net) - the only relief route that works for non-earners.