£100k Tax Trap Calculator
See how the £100k–£125,140 personal allowance taper creates a 60% effective tax rate. Visualise the trap and plan around it.
Adjusted net income
£110,000
Costs you £6,200/yr
Your adjusted net income
£110,000
Costs you £6,200/yr in lost allowance
Personal allowance
£7,570
The dip: how earning more can cost you
How to escape the trap
Reduce your adjusted net income to £100,000 to restore your full personal allowance.
Via salary sacrifice — saves tax, NI, and restores PA. Effective relief rate: 62%.
You may have unused pension allowance from previous years (up to £60k/yr, carry forward up to 3 years).
Gift Aid donations are grossed up by 1.25× when calculating ANI.
Other salary sacrifice options
Electric vehicle scheme, Cycle to Work, technology schemes — all reduce ANI.
Note: EIS, SEIS, and VCT investments reduce your tax bill but do NOT reduce your ANI — they won't help escape the trap.
Before vs After: pension to £100k ANI
| Current | Optimized | Saving | |
|---|---|---|---|
| Gross | £110,000 | £110,000 | — |
| Pension | £0 | £10,000 | +£10,000 |
| Personal allowance | £7,570 | £12,570 | +£5,000 |
| Income tax | £33,432 | £27,432 | −£6,000 |
| National Insurance | £4,211 | £4,011 | −£200 |
| Net pay | £72,357 | £68,557 | −£3,800 |
| Total value (pay + pension) | £72,357 | £78,557 | +£6,200 |
By contributing £10,000/yr to pension, you're £6,200/yr better off — and building retirement savings.