Salary Sacrifice and the £100,000 Tax Trap 2026/27
Written by James Whitfield · Updated August 2026 · Checked against 2026/27 HMRC rates.
Earn above £100,000 and you start losing your personal allowance. By £125,140 it is gone entirely. In the £100,000–£125,140 band the effective marginal tax rate is 60%.1 Salary sacrifice into a pension is the most effective financial action available to anyone sitting in that range. This page explains the mechanics and the numbers.
- Between £100,000 and £125,140 you lose £1 of Personal Allowance per £2 earned — a 60% effective rate.1
- Sacrifice reduces adjusted net income £-for-£, saving tax at that 60% rate and restoring the allowance.1
- At £108,000, an £8,000 sacrifice restores the full allowance for a net cost of £3,040.2
- Under £100,000 it also reopens 30-hours free childcare — often worth £5,000+ on top.
- Very high earners should check the tapered annual allowance before sacrificing large sums.3
How the 60% trap works
The personal allowance for 2026/27 is £12,570. HMRC withdraws £1 of personal allowance for every £2 of income above £100,000. At £125,140 the allowance is fully gone (£25,140 ÷ 2 = £12,570 lost).1
The 60% rate arises because every additional £2 of income is taxed twice. Directly: 40% higher rate = £0.80 on £2. Indirectly: that £2 triggers £1 of allowance loss, which would have sheltered £1 from 40% tax — an extra £0.40. Total: £1.20 tax on £2, or 60%.
For Scottish taxpayers the rates differ. Scotland has a 42% higher rate from £43,663 and different threshold interactions. But the principle is the same — personal allowance withdrawal creates a super-high effective rate in the withdrawal band.
How salary sacrifice solves it
Salary sacrifice reduces your adjusted net income (ANI). That is the figure HMRC uses for the personal allowance withdrawal calculation. Every pound sacrificed above £100,000 reduces ANI by £1, restoring £0.50 of personal allowance and saving tax at the 60% effective rate.
So a £10,000 pension sacrifice at a salary of £108,000 saves: 60% × £8,000 (clearing the taper zone) + 40% × £2,000 (the remaining sacrifice in the standard higher-rate band) = £4,800 + £800 = £5,600 in income tax. Add employee NI: £10,000 × 2% = £200. Total saving: £5,800. Net cost of the £10,000 contribution: only £4,200 — a 58% discount.
Worked example: £108,000 salary
At £108,000 the personal allowance is already tapered to £8,570 (£12,570 − £4,000). Sacrificing £8,000 pulls adjusted net income back to £100,000 and restores the full allowance:1
| Sacrificed into pension | £8,000 |
| Income tax saved — 60% effective rate1 | −£4,800 |
| Employee NI saved — 2%2 | −£160 |
| Net cost of an £8,000 pension top-up (≈ £253/month) | £3,040 |
£667/month goes into the pension while take-home falls by only £253/month — the other £413 is tax and NI you keep.
Worked example: £120,000 salary
Salary: £120,000. ANI before sacrifice: £120,000. Personal allowance reduced by (£120,000 − £100,000) ÷ 2 = £10,000. Effective personal allowance: £2,570.
Sacrifice £20,000 to bring ANI to £100,000. The full £20,000 falls in the 60% zone. Tax saving: 60% × £20,000 = £12,000. NI saving: 2% × £20,000 = £400. Total saving: £12,400. Net cost of the £20,000 contribution: £7,600. That is 38p in every pound from take-home, or a 62% immediate return on every pound of net pay reduction.
Note: this calculation assumes no other adjustments such as Gift Aid. ANI is gross salary minus pension sacrifice minus Gift Aid donations and some other deductions. Significant Gift Aid donations also reduce ANI and may mean less sacrifice is needed to clear the threshold.
30 hours free childcare: a further incentive
The 30-hour free childcare entitlement for 3–4 year olds requires ANI below £100,000. Lose it and you lose 15 hours per week. Depending on your area that can be worth £5,000–£10,000 per year. Salary sacrifice that brings ANI below £100,000 simultaneously restores the entitlement and saves tax at 60% on the withdrawal band income.
For a parent with a 3- or 4-year-old and income of £103,000, sacrificing £3,000 does three things: (1) 60% income tax saving on £3,000 = £1,800; (2) NI saving = £60; (3) 30-hour childcare restored, potentially worth £5,000+. Total benefit: £6,860+ from a sacrifice that only reduces take-home by £1,140.
Using the calculator
Use our £100k salary sacrifice calculator to model the exact saving at your income level. Enter your gross salary and sacrifice amount and the calculator shows the personal allowance restored, income tax saving, NI saving and net monthly cost. For a full breakdown, use the main salary sacrifice calculator.
These calculators model England/Wales/NI rates. Scottish taxpayers face different band structures. If your income is very high and the tapered annual allowance is in play, take regulated financial advice before making large sacrifice decisions.
Frequently asked questions
Why is the tax rate 60% between £100,000 and £125,140?
Every £2 you earn in that band is taxed at 40% (80p) and also removes £1 of Personal Allowance, which is then taxed at 40% (another 40p). That's £1.20 of tax on £2 of income — a 60% effective rate. It's the highest marginal rate most earners will ever face.
How much should I sacrifice to escape the trap?
Enough to bring your adjusted net income down to £100,000. If you earn £108,000, that's £8,000; at £120,000 it's £20,000. Every pound of that sacrifice saves tax at 60% plus 2% NI, and restores part of your Personal Allowance. Gift Aid donations also reduce adjusted net income, so factor those in.
Does the £100,000 threshold use my gross salary or something else?
It uses adjusted net income, which is broadly your taxable income minus gross pension contributions and Gift Aid. Because salary sacrifice reduces your taxable pay directly, it lowers adjusted net income pound for pound — which is what makes it so effective at this income level.
Is there a childcare angle too?
Yes, and it's a big one for parents. 30-hours free childcare and Tax-Free Childcare both require each parent's adjusted net income to be under £100,000. Sacrificing below the threshold restores them — often worth £5,000 or more a year on top of the 60% tax saving.
Can I sacrifice so much that I go below £100,000 for nothing?
You can keep sacrificing below £100,000, but the extra saving drops to the normal higher-rate 40% (plus 2% NI) once you're clear of the taper zone. The 60% band only applies between £100,000 and £125,140, so that's where each pound of sacrifice works hardest. Also keep total pension inputs within your annual allowance.
Related guides and calculators
£100k trap calculator, higher-rate taxpayer guide, annual allowance guide, childcare and salary sacrifice, pension calculator
Sources & references
Every headline figure in this guide is checked against the official HMRC and GOV.UK pages below and reflects the confirmed 2026/27 tax year. Each link opens the relevant official page in a new tab.
- Income Tax: income over £100,000 ↗ https://www.gov.uk/income-tax-rates/income-over-100000
- Income Tax rates and Personal Allowances ↗ https://www.gov.uk/income-tax-rates
- Pension annual allowance ↗ https://www.gov.uk/tax-on-your-private-pension/annual-allowance
- Salary sacrifice and the effects on PAYE (HMRC) ↗ https://www.gov.uk/guidance/salary-sacrifice-and-the-effects-on-paye