Why 60%?
For every £2 of adjusted net income over £100,000 you lose £1 of personal allowance. Each extra £1 therefore costs 40p tax plus 40% on the 50p of allowance lost = 60p. Pension contributions or Gift Aid reduce adjusted net income and can also keep 30 hours of free childcare and Tax-Free Childcare.
FAQ
How do I avoid the 60% tax trap?
Pay enough into a pension (salary sacrifice or relief at source) to bring adjusted net income down to £100,000.
Sources (checked 6 Nov 2026): HMRC personal allowance taper.