How it works
£100,000 salary: take-home pay and the 60% trap
£100,000 is a landmark salary in the UK tax system. It is the exact threshold where the Personal Allowance begins to taper: for every £2 earned above £100,000, you lose £1 of your tax-free Personal Allowance. At exactly £100,000, your allowance is still fully intact at £12,570.
Without any pension or adjustment, your take-home on £100,000 in England for 2025/26 is approximately £68,557/year (£5,713/month).
| Item | Annual | Monthly |
|---|---|---|
| Gross salary | £100,000.00 | £8,333.33 |
| Personal Allowance (intact at £100k) | £12,570.00 | £1,047.50 |
| Basic-rate IT (20% × £37,700) | −£7,540.00 | −£628.33 |
| Higher-rate IT (40% × £49,730) | −£19,892.00 | −£1,657.67 |
| NI at 8% (up to £50,270) | −£3,016.00 | −£251.33 |
| NI at 2% (£50,271–£100,000) | −£994.60 | −£82.88 |
| Take-home pay | £68,557.40 | £5,713.12 |
The 60% effective marginal rate — explained
The moment your income exceeds £100,000, something unusual happens. Earning £1 above £100,000 triggers two simultaneous tax costs:
- 40% higher-rate Income Tax on that £1 of income
- 20% effective tax on lost allowance — losing 50p of Personal Allowance means 50p of previously tax-free income now gets taxed at 40%, adding another 20p of tax
- Combined: 60p of tax on every £1 earned between £100,000 and £125,140
Worked example of the trap
Imagine your salary rises from £100,000 to £105,000. Your allowance tapers from £12,570 to £10,070 (£2,500 reduction for a £5,000 income increase). That means £2,500 of previously tax-free income now faces 40% tax (£1,000 extra). Plus the £5,000 extra income itself pays 40% (£2,000). Total extra tax on a £5,000 raise: £3,000 — an effective 60% rate.
How to escape it
The standard approach: make a pension salary sacrifice of the amount above £100,000. A £105,000 earner who sacrifices £5,000 into a pension effectively earns £100,000 for tax purposes, eliminating the trap and putting £5,000 into their pension instead of losing £3,000 to tax.
Child Benefit at £100,000
At £100,000, the High Income Child Benefit Charge is at maximum — your adjusted net income is £20,000 above the £80,000 ceiling. This means 100% of Child Benefit is clawed back through your Self Assessment.
Pension contributions that reduce your adjusted net income below £80,000 would begin to restore Child Benefit. Below £60,000, it is fully restored.
Student loan repayments at £100,000
Student loan deductions at this income level are large. They cannot be avoided through salary sacrifice.
| Plan | Annual repayment | Monthly |
|---|---|---|
| Plan 1 | £6,654 (9% × £73,935) | £554.50 |
| Plan 2 | £6,438 (9% × £71,530) | £536.50 |
| Plan 4 (Scotland) | £6,053 (9% × £67,255) | £504.60 |
| Plan 5 | £6,750 (9% × £75,000) | £562.50 |
| Postgraduate | £4,740 (6% × £79,000) | £395 |
Why pension contributions are transformational at £100,000
A £100,000 earner who makes a £10,000 gross pension contribution achieves:
- Adjusted net income drops to £90,000 — taking you out of the most aggressive part of the allowance taper
- Personal Allowance restores by £5,000 — saving an extra £2,000 in tax
- Total tax saving on £10,000 pension: approximately £4,200
- Effective pension cost: £5,800 net take-home reduction to put £10,000 in your pension