Salary Sacrifice Optimiser
Salary sacrifice can be one of the higher-leverage moves in UK personal finance. Work out how much take-home you would lose, how much pension you would gain, and whether the trade-off looks worth it for your circumstances. This is general information, not personal advice.
Your income
Sacrifice and employer
Net wealth gain (per year)
£2,100
Take-home change
-£2,900
Pension change
£5,000
Leverage on sacrifice
42%
Without sacrifice
- Gross income
- £60,000
- Income tax
- -£11,432
- Employee NI
- -£3,210
- Take-home
- £45,358
- Pension paid in
- £3,000
With sacrifice
- Adjusted gross
- £55,000
- Income tax
- -£9,432
- Employee NI
- -£3,110
- Take-home
- £42,458
- Pension paid in
- £8,000
Frequently Asked Questions
What is salary sacrifice?
Salary sacrifice is a contractual agreement where you give up part of your gross salary in exchange for a non-cash benefit, most commonly a pension contribution. The sacrificed amount is paid directly into your pension by your employer, so you do not pay income tax or National Insurance on it. The employer also saves their NI on the sacrificed amount, and some employers pass that saving through to your pension as a bonus contribution.
What is the 60% tax trap?
Between £100,000 and £125,140 of income, every £2 you earn loses £1 of your Personal Allowance. The effective marginal tax rate in this band is around 60% (40% income tax plus the lost PA effectively taxed at 20% as well). Add 2% National Insurance and around 62p of every additional pound is lost to tax. Salary sacrifice that brings adjusted net income back to £100,000 restores the Personal Allowance, which is why many higher earners look at this band closely. Whether it suits your circumstances depends on your wider position and is not advice.
How much should I sacrifice?
The right amount depends on your priorities, cash needs and scheme rules. In rough order of marginal-rate leverage: people above £100,000 often look at sacrificing back to £100k (60% trap), people claiming Child Benefit at the £60,000 to £80,000 charge band, and people who want to drop below the £50,270 higher-rate threshold. Below the higher-rate threshold the maths is less dramatic but typically still favourable: every £1 sacrificed costs roughly 72p of take-home and adds £1 to the pension (plus any employer match). Pension money is locked away until at least age 57, so this is not advice - it is a framework for thinking about it.
Will salary sacrifice affect my mortgage application?
Yes - lenders use your gross taxable salary for affordability assessment, and a salary sacrifice reduces that figure. Some lenders include pension contributions in the "income" figure but most do not. If you are about to apply for a mortgage, consider pausing the sacrifice for 6-12 months to maximise your reported income. After completion, restart it.
Can I sacrifice into anything other than pension?
Yes, though the tax treatment varies. Common other sacrifices: childcare vouchers (mostly phased out, replaced by Tax-Free Childcare), Cycle to Work scheme (full income tax and NI relief), electric vehicle leases via the company (very tax-efficient since the BIK rate on EVs is low), additional holiday days. Pension is the headline because it has the biggest tax saving and the largest scheme limits.
What about the pension annual allowance?
The pension annual allowance is £60,000 for most people in 2026/27, tapering down to as little as £10,000 for very high earners (income over £260,000). Salary sacrifice contributions count toward the annual allowance - exceeding it triggers a tax charge that wipes out the saving. If your sacrifice plus employer contributions approach £60,000, check the carry-forward rules (you can roll up to 3 prior years of unused allowance).
Does salary sacrifice affect my State Pension?
Possibly. State Pension entitlement is built up through National Insurance "qualifying years", which generally require earning above the Lower Earnings Limit (around £6,500 a year - check the latest figure on gov.uk). If your sacrifice takes your reported salary below the LEL, you can miss a qualifying year, which reduces your eventual State Pension. A common approach is to keep reported earnings above the LEL and ideally above the primary threshold (£12,570).
What about the Child Benefit High Income Charge?
Above £60,000 of "adjusted net income" (which is income after pension contributions including sacrifice), parents start paying back Child Benefit. The taper runs at 1% per £200 of additional income, so at £80,000 the entire Child Benefit is being clawed back. For a family with two children claiming Child Benefit (around £2,300/year), bringing income back to £60,000 via sacrifice is worth £2,300/year in protected Child Benefit on top of all the normal sacrifice savings.
Is salary sacrifice worth it for a basic-rate taxpayer?
Often yes, though the maths is less dramatic. A basic-rate worker typically saves around 28% (20% income tax plus 8% NI) on each pound sacrificed, so £1,000 in the pension can cost around £720 of take-home - roughly a 39% uplift before any employer match. A common framework is to capture the full employer match through sacrifice first, then consider further savings via a Stocks and Shares ISA where the money is not locked away until 57. This is general information, not advice.
Can I salary sacrifice down to minimum wage?
No. NMW is a legal floor and your employer must refuse any sacrifice that would breach it. The optimiser caps its recommendation at the NMW-equivalent annual salary for your contracted hours. For a standard 37.5-hour week from April 2026 that works out at around £24,785 (£12.71 per hour for the 21-plus rate). If your contract is part-time the floor is proportionally lower.
Can my employer refuse to offer salary sacrifice?
Yes. Sacrifice is optional for employers. If yours does not run a scheme there is no legal route to force one. The next best thing is a standard relief-at-source pension contribution and a self-assessment claim for the higher-rate portion if you are above the basic-rate threshold. The numbers are slightly worse than sacrifice but the gap is small for basic-rate workers.
Related reading
Salary sacrifice pension UK guide
The full mechanics behind the numbers this optimiser produces.
The 60% tax trap explained
Why sacrificing inside £100k-£125,140 can be one of the higher-leverage moves in UK personal finance.
SIPP vs workplace pension
Where the sacrificed contribution should land for the best long-run return.
What are qualifying earnings?
Why your headline "8%" workplace match is rarely 8% of full salary, and what sacrifice fixes.
How salary sacrifice into a pension actually saves you tax
Salary sacrifice typically trades a portion of your gross salary for a direct employer pension contribution before income tax or National Insurance is calculated. For a higher-rate taxpayer, every £1,000 sacrificed can cost around £580 of take-home pay (based on saving 40% income tax plus 2% employee NI = 42%) while £1,000 lands inside the pension. If your employer also shares any of their saved 13.8% employer NI back into the pot, the multiplier can be larger. Whether sacrifice suits you depends on your scheme rules, age, wider tax position and access needs.
The calculator scans a range of sacrifice amounts and highlights the largest figure that would not push your post-sacrifice salary below the National Minimum Wage. It cannot judge whether that amount is right for you - that depends on factors like mortgage plans, emergency cash needs, scheme-specific rules and other income-based assessments.
Things to think about: sacrifice reduces your reference salary, which can have knock-on effects on borrowing capacity at remortgage, statutory redundancy pay, statutory maternity pay calculations and life cover written as a multiple of salary. The optimiser flags when your sacrifice is high enough that one of these might be affected. If you are unsure how it interacts with your situation, consider speaking to a regulated financial adviser or pensions specialist.
The complete guide
Salary Sacrifice Calculator UK: How Much Should You Sacrifice?
UK salary sacrifice calculator for 2026/27. Find the exact amount that maximises pension uplift without breaching NMW, mortgage limits or annual allowance.
For a higher-rate taxpayer, £1,000 sacrificed into pension typically costs around £580 of take-home and lands £1,000 in the pot. That works out at roughly a 72% effective uplift before the employer match, before any NI share, and before any investment growth (illustrative figures based on 2026/27 bands).
It is one of the more under-used levers in UK personal finance, and most workplace schemes do not tell you a suggested number. The salary sacrifice optimiser runs your salary against the 2026-27 tax bands, scans sacrifice amounts from zero up to the National Minimum Wage floor, and surfaces the figure that maximises net wealth on the calculator's own metric. It is a planning tool, not financial advice.
This guide explains the mechanics behind that number, the marginal rate steps that make some bands more efficient than others, and the traps that can catch a sacrifice you set up without thinking. If you are unsure how this fits your wider position, consider speaking to a regulated financial adviser.
Contents
- What salary sacrifice actually does
- Effective marginal rates by income band
- How the optimiser picks the number
- Worked example: a £60k earner sacrificing £5k
- The traps: NMW, SMP, mortgages and the £100k cliff
What salary sacrifice actually does
Salary sacrifice is a contractual change to your pay. You agree with your employer that part of your gross salary will no longer be paid as cash. Instead it goes straight into your workplace pension as an employer contribution. The crucial word is contractual. This is not you paying into a pension after tax. It is your salary being lower, full stop, with the difference paid into your pension by your employer before any tax or NI calculation runs.
Because the sacrificed amount never appears as your earnings, HMRC never sees it as income. You do not pay income tax on it. You do not pay employee NI on it. Your employer does not pay employer NI (13.8%) on it either, and the better employers pass some or all of that 13.8% saving back into your pension on top.
Compare that with the alternative. A "relief at source" personal pension contribution, the type most personal SIPPs and Lifetime ISAs use, is paid from money that has already been through PAYE. HMRC then refunds the basic rate (20%) at source and you have to reclaim the higher-rate portion through self assessment. You get there in the end but you have already paid employee NI on it, your employer has already paid employer NI, and you are out of pocket until the rebate arrives.
For a basic-rate worker the gap between the two is small. For a higher-rate worker it is meaningful. For anyone inside the £100k Personal Allowance taper it is enormous. The SIPP vs workplace pension guide walks through where the sacrificed contribution should sit for the best long-run return.
Effective marginal rates by income band
The reason sacrifice pays so well is that UK marginal rates jump at predictable points, and sacrifice attacks the highest rate on your last pound earned. The 2026-27 bands look like this.
- £12,570 to £50,270 (basic rate): 20% income tax plus 8% employee NI. Effective marginal rate around 28%. £1,000 sacrificed typically costs about £720 of take-home and adds £1,000 to the pension.
- £50,270 to £100,000 (higher rate): 40% income tax plus 2% employee NI. Effective marginal rate around 42%. £1,000 sacrificed typically costs about £580 of take-home and adds £1,000 to the pension - the 72% uplift in the headline.
- £100,000 to £125,140 (Personal Allowance taper): 40% income tax, 2% NI, plus the £1-for-every-£2 withdrawal of the £12,570 Personal Allowance. Effective marginal rate around 62%. £1,000 sacrificed typically costs about £380 of take-home and adds £1,000 to the pension - roughly a 163% uplift on the cash cost.
- £125,140+ (additional rate): 45% income tax plus 2% NI. Effective marginal rate around 47%. £1,000 sacrificed typically costs about £530 of take-home and adds £1,000.
- £60,000 to £80,000 (with Child Benefit): standard higher-rate plus the High Income Child Benefit Charge clawback. For a two-child family the clawback over that £20k band roughly layers another marginal cost onto each pound earned. (Exact figure varies with current Child Benefit rates - check gov.uk.)
The 60% tax trap calculator drills into the taper zone specifically. For salaries between £100k and £125,140 the taper means sacrifice can be unusually efficient compared with other bands, though whether to use it remains an individual decision.
How the optimiser picks the number
The optimiser runs the numbers across a range of sacrifice amounts and surfaces the one that scores best on its own net-wealth metric. That is not a recommendation - it is the output of a model.
Internally it scans from £0 up to the largest amount that would still leave your salary above the National Minimum Wage floor. For each candidate it computes the resulting take-home, the resulting pension contribution (including any employer match and any shared employer NI), and the net wealth change. It then ranks them.
The suggested number is not always the maximum possible. The tool will:
- Stop at £100,000 if you are currently above it, because that is where the 60% Personal Allowance taper ends and further sacrifice drops to a 42% marginal rate.
- Stop at £60,000 if you claim Child Benefit, because that is where the High Income Child Benefit Charge starts.
- Stop at £50,270 if you are currently above it and there is no taper to exploit, on the basis that basic-rate sacrifice is generally less efficient than the same money in a Stocks and Shares ISA, which can be accessed before age 57.
- Refuse to drop you below the NMW floor regardless of how attractive the marginal rate looks.
The pension match calculator covers the employer-match leg of this in detail. The pension carry-forward calculator is what you reach for if the optimiser's recommended number exceeds your current-year annual allowance.
Worked example: a £60k earner sacrificing £5k
Take a worker on £60,000 salary with no bonus, a 5% employer match and zero NI sharing. They are £9,730 into the higher-rate band.
Without sacrifice:
- Gross income: £60,000
- Income tax: about £11,432
- Employee NI: about £3,792
- Take-home: about £44,776
- Pension (5% employer + 5% employee from net): £6,000 going in, £3,000 from the employee net
With £5,000 sacrificed:
- Adjusted gross: £55,000
- Income tax: about £9,432 (£2,000 saved at 40%)
- Employee NI: about £3,692 (£100 saved at 2%)
- Take-home: about £41,876
- Pension: the original £6,000 plus the full £5,000 sacrificed = £11,000
Take-home falls by around £2,900. Pension rises by £5,000. That works out at a net wealth change of about plus £2,100 a year on a sacrifice that costs roughly £242 a month in cash. Over five years that compounds to around £10,500 of extra notional wealth before any investment return inside the pension. Over a longer career the figures can become substantial, though investment returns are not guaranteed and pension money is locked away until at least age 57.
If the employer shares half their 13.8% NI saving back into the pot the gain rises further. £5,000 sacrificed saves the employer £690 of NI; half of that, £345, added to the pension takes the annual net wealth gain to around £2,400 on these illustrative inputs. It can be worth asking HR what your scheme does.
The traps: NMW, SMP, mortgages and the £100k cliff
Sacrifice cuts the salary your employer reports on every form they file about you. Most of the time nobody notices. The trap is the day they do.
National Minimum Wage. A salary sacrifice that would push your contractual hourly rate below NMW is unlawful. Your employer will refuse it. From April 2026 the NMW floor is £12.71 an hour for workers aged 21 and over (per gov.uk), so on a 37.5-hour week the minimum reported salary works out at around £24,785. The optimiser checks this automatically.
Statutory Maternity Pay. SMP for the first six weeks is 90% of your average weekly earnings in the eight weeks before the qualifying week. If those eight weeks fall after a sacrifice kicks in, your reference earnings drop and your SMP drops with them. The standard rate from week seven onwards is £194.32 a week (gov.uk 2026-27), but the higher-rate first six are based on actual reported pay. Pausing or reducing sacrifice in the year before a planned pregnancy is a common move.
Mortgage affordability. Lenders assess affordability on gross taxable salary. A £5,000 sacrifice can shave £20,000 off your maximum borrowing on a 4x income multiple. Some lenders add pension contributions back into the affordability calculation, most do not. If you are planning to remortgage or buy in the next twelve months, run the take-home pay calculator on a paused-sacrifice scenario and compare.
Statutory Sick Pay, redundancy, life cover. SSP, statutory redundancy and any death-in-service multiple of salary all index off your reduced salary. The numbers are small for most workers but worth knowing.
The £100,000 cliff. This one works in your favour. Sacrificing from above £100,000 down to exactly £100,000 restores the £12,570 Personal Allowance you would otherwise lose, and the effective return on those pounds is around 62%. Few other moves in UK personal finance hit that marginal rate, which is why higher earners in this band often consider it - whether it is right for you depends on your wider plans, access needs and scheme rules. The what are qualifying earnings guide explains why the workplace-pension default rarely catches this on its own.