If your income lands between £100,000 and £125,140, you are sitting inside the most punishing tax band in the UK — and almost nobody tells you it exists until after the damage is done.
The headline rate is 40%. But in this band, your effective marginal rate is 60%. Every £2 you earn above £100,000 costs you £1 in personal allowance, and you pay 40% tax on that lost allowance as well as 40% on the income itself. That is not a typo. It is not a rounding error. It is deliberate design, baked into the tax code, and it has been quietly catching out well-paid professionals for over a decade.
The good news: salary sacrifice into a pension is a near-perfect escape hatch. Used correctly, it pulls your adjusted net income below £100,000, restores your full personal allowance, and turns a 60p-in-the-pound tax hit into a 40% deduction. This article explains exactly how it works — the maths, the mechanics, and the timing.
How the Personal Allowance Taper Works
Every UK taxpayer gets a tax-free personal allowance — currently £12,570 for the 2025/26 tax year. It means the first £12,570 of your income is charged at 0%.
But once your adjusted net income exceeds £100,000, HMRC starts clawing it back. For every £2 of income above £100,000, you lose £1 of personal allowance. By the time your income reaches £125,140, the allowance is gone entirely.
Run the maths and the effective marginal rate becomes clear:
- You earn £2 extra above £100,000
- You lose £1 of personal allowance
- That £1 was sheltered from tax — now it is not, so you pay 40% on it (£0.40)
- You also pay 40% on the £2 you actually earned (£0.80)
- Total tax on £2 of income: £1.20
- Effective marginal rate: 60%
The band runs for £25,140 (from £100,000 to £125,140). Over that stretch you lose the full £12,570 allowance. In tax terms, you pay an extra £5,028 in income tax compared to what you would pay if the taper did not exist.
Who Is Affected
This is no longer a niche problem. Wage inflation, particularly in technology, finance, medicine, law, and senior public sector roles, has pushed a large cohort into this band for the first time. According to HMRC data, over 800,000 taxpayers now have income above £100,000 — and that number is rising every year as thresholds are frozen while salaries creep upward.
The taper catches:
- Employees with salary, bonus, or share-based income that tips them over £100,000
- Self-employed professionals with a profitable year
- Company directors taking a mix of salary and dividends
- Contractors inside IR35 whose deemed income lands in the band
- Anyone receiving a windfall — a bonus, a property sale, an inheritance — that pushes adjusted net income above the threshold
Note that it is adjusted net income that matters, not gross pay. Pension contributions, Gift Aid donations, and other relievable payments reduce your adjusted net income. That is exactly where the planning opportunity sits.
Worked Example 1: The £110,000 Earner
Alex earns £110,000 in salary. No pension contributions. Here is the tax position without any planning:
- Income above £100,000: £10,000
- Personal allowance lost: £5,000 (half of £10,000)
- Remaining personal allowance: £7,570
- Income tax payable: significantly higher than a straight 40% calculation suggests
The £5,000 of lost allowance is taxed at 40%, adding £2,000 of extra tax on top of the standard 40% charge on the £10,000 overage. Alex pays an effective marginal rate of 60% on every pound between £100,000 and £110,000.
Now Alex makes a £10,000 pension contribution via salary sacrifice. Adjusted net income drops to £100,000 exactly. The full personal allowance is restored. Alex saves approximately £6,000 in income tax compared to doing nothing — a return of 60p for every pound put into the pension, before any employer NI savings.
Worked Example 2: The Bonus That Blew Past the Threshold
Sarah has a base salary of £95,000. She receives a £20,000 bonus in March, taking her total to £115,000. She did not expect it and has made no pension contributions this year.
The band between £100,000 and £115,000 is fully within the taper zone. Her effective marginal rate on the £15,000 above the threshold is 60%. Without action, she pays approximately £9,000 in extra tax on that portion.
If Sarah makes a £15,000 pension contribution before 5 April (or requests her employer apply it via salary sacrifice to her bonus), her adjusted net income falls back to £100,000. She recovers approximately £9,000 in tax relief. The pension contribution effectively costs her £6,000 net — for £15,000 of pension savings.
Salary Sacrifice: How It Actually Works
Salary sacrifice is a formal arrangement between you and your employer. You agree to take a lower salary in exchange for the employer making an equivalent contribution to your pension. Because the contribution never reaches your pay packet, it never forms part of your gross income — and so your adjusted net income is lower from the outset.
This is more tax-efficient than making a personal pension contribution (where you earn the income, pay tax on it, then reclaim the tax via your Self Assessment return). With salary sacrifice:
- The contribution reduces gross pay before tax and National Insurance are calculated
- You save employer NI (13.8%) which your employer may pass on as additional pension contribution
- You save employee NI (2% above £50,270, or 8% below it)
- Your adjusted net income is reduced, potentially restoring your personal allowance
Not every employer offers salary sacrifice. If yours does not, a personal pension contribution achieves the same adjusted net income reduction — you just claim the additional higher-rate relief via Self Assessment rather than at source. Either way, the personal allowance is restored.
The Maths on a Full £25,140 Sacrifice
If your income is at or above £125,140 and you want to fully escape the trap, you need to sacrifice enough to bring adjusted net income below £100,000. That means contributions of at least £25,140 above whatever pension saving you are already making.
At a 60% effective marginal rate, contributing £25,140 produces:
- Tax saving: approximately £15,084 (60% of £25,140)
- Net cost of contribution: approximately £10,056
- Pension pot growth: £25,140 (at minimum — employer top-up may increase this)
You get £25,140 of pension savings for an out-of-pocket cost of roughly £10,056. That is a 150% immediate return before any investment growth, employer matching, or compounding.
The annual pension contribution allowance for 2025/26 is £60,000 (or 100% of UK earnings, whichever is lower). Unused allowance from the previous three tax years can be carried forward. Most people in this income band have significant carry-forward headroom.
Timing: Before or After the Tax Year Ends?
The key deadline is 5 April. Pension contributions made on or before that date count against the current tax year. Anything after 5 April falls into the next year.
For salary sacrifice, the timing is determined by your payroll — contributions deducted from your April payslip will generally count for that tax year. Check with your employer and pension provider, particularly if you are making a large lump-sum top-up.
For personal pension contributions (where you pay in and reclaim tax relief via Self Assessment), the contribution date is the date the payment clears. Bank transfers to a SIPP typically clear within a working day, but do not leave it to the last moment.
If you have already missed the current tax year, do not wait until next March to act. Set up a salary sacrifice arrangement from the start of the new tax year and model the full year's contributions now. Mid-year adjustments are harder to get right and employers have varying timescales for processing changes.
Other Ways to Reduce Adjusted Net Income
Pension contributions are the most powerful tool, but not the only one. Other methods that reduce adjusted net income include:
- Gift Aid donations: Charitable donations made via Gift Aid are deducted from adjusted net income. A £5,000 donation reduces adjusted net income by £5,000, saving up to £3,000 in tax if it pulls you out of the taper zone.
- Venture Capital Trust (VCT) investments: Offer 30% income tax relief, though they carry higher investment risk and the relief is not applied against adjusted net income in the same way as pension contributions.
- Enterprise Investment Scheme (EIS): Similarly offers 30% tax relief and can defer capital gains, but again carries risk and specific conditions.
- Cycle to Work scheme and other salary sacrifice benefits: Reduce gross salary, though typically by smaller amounts than pension sacrifice.
None of these replace the pension contribution as the primary lever for most people. They can supplement it if you are already maximising pension contributions or have specific circumstances that limit pension options.
Child Benefit: The Extra Sting
If you or your partner claim Child Benefit and your adjusted net income exceeds £60,000, you are subject to the High Income Child Benefit Charge (HICBC). The charge claws back 1% of the Child Benefit received for every £200 of income above £60,000, with the full benefit removed at £80,000.
This creates a secondary marginal rate problem operating below the personal allowance taper zone. If you have income in the £60,000-£80,000 range with children, pension contributions can reduce adjusted net income below the threshold and restore the benefit — worth up to £2,212.60 per year for two children in 2025/26.
Stacking pension contributions to address both the Child Benefit charge and the personal allowance taper is a common planning strategy for families with income in the £80,000-£125,140 range.
What Happens If You Do Nothing
The PAYE system is not designed to flag this. If you are an employee, your employer withholds tax at the standard higher-rate with adjustments for your tax code — but the personal allowance taper is not automatically applied at source in most cases. You will either see a revised tax code (starting with a lower personal allowance figure) or a Self Assessment tax bill at the end of the year.
The Self Assessment bill for someone earning £125,140 with no planning is roughly £5,028 higher than it would be without the taper. Many people see this as a lump sum demand in January — 9 months after the tax year ended — with no clear explanation of why their bill is so much larger than expected.
If you are in this band and not submitting a Self Assessment return, you need to. The taper creates an underpayment that HMRC will collect — either via an adjusted tax code in subsequent years or a formal payment demand. Burying your head does not make it go away.
When to Get Professional Advice
The personal allowance taper is well-understood territory for any competent financial adviser or tax accountant. If your income is consistently above £100,000, the value of advice comfortably outweighs the cost.
Scenarios where professional input is particularly valuable:
- Your income is variable (large bonus, equity vest, freelance income) and you need to model contributions before year-end
- You are a director taking salary and dividends and want to optimise the mix
- You have significant carry-forward pension allowance and want to use it strategically
- You are within 5-10 years of retirement and want to balance pension funding against other goals
- Your employer does not offer salary sacrifice and you need to navigate personal pension contributions efficiently
A one-off financial planning session typically costs £300-£800. Against a potential tax saving of £5,000-£15,000, the ROI is obvious.
→ Find a regulated financial adviser via Unbiased — the UK's largest adviser matching service. Independent advisers specialising in income tax planning, pension contributions, and higher-rate relief.
Choosing a Pension Provider
If you need to open a SIPP (Self-Invested Personal Pension) to make personal contributions — because your employer scheme is limited or you want flexibility — here are the main options used by higher earners:
- PensionBee — consolidates old workplace pensions and accepts personal contributions. Transparent flat fees, app-based management, straightforward for lump-sum contributions before 5 April.
- Hargreaves Lansdown SIPP — widest investment choice, strong research tools. Standard platform for those who want full control over underlying funds.
- AJ Bell SIPP — lower platform fees than HL at larger balances, good fund and share choice. Worth comparing at balances above £50,000.
For most people in the £100k-£125k band, the tax saving from the contribution is more important than which provider you choose. Open an account, make the contribution before 5 April, and optimise the investment allocation later.
Summary: The Numbers That Matter
If your income is between £100,000 and £125,140, here is what you need to hold in your head:
- Your effective marginal rate in this band is 60%
- Every £1 you put into a pension in this band costs you 40p net
- Salary sacrifice is more efficient than personal contributions because it saves NI as well as income tax
- The 5 April deadline is hard — contributions after that date fall into the next tax year
- The annual pension allowance is £60,000; you can carry forward unused allowance from the prior three years
- If you have not submitted a Self Assessment return, you probably owe more tax than you think
The 60% trap is one of the clearest planning opportunities in the UK tax code. You are not avoiding tax — you are using a government-sanctioned incentive exactly as intended. The pension system exists specifically to reward long-term saving. The personal allowance taper was not designed to be a trap; it was designed to limit the allowance for high earners. The trap is that nobody explains it clearly when your salary first crosses £100,000.
Now you know. The question is what you do about it before 5 April.
This article is for informational purposes only and does not constitute financial advice. Tax rules can change and depend on individual circumstances. Consult a regulated financial adviser or qualified tax accountant before making decisions.