Why is the £100k–£125,140 zone special?
In this zone the Personal Allowance tapers (losing £1 per £2 of income) on top of the 40% higher-rate band. The combined effective marginal Income Tax rate is 60%. Pension contributions can restore the PA — making this the single most tax-efficient salary band for pension contributions in the UK.
How is relief actually given?
Three mechanisms: (1) Relief at source — your provider claims back basic-rate (20%); higher/additional rate is claimed via Self Assessment. (2) Net pay arrangement — contribution comes off gross salary before tax, full relief applied immediately. (3) Salary sacrifice — contribution comes from pre-tax salary, also saving NI.
What is carry forward?
If you didn't use your full annual allowance in any of the previous 3 tax years, you can carry forward the unused amount (provided you were a member of a registered pension scheme during those years). Useful for big one-off contributions. Not modelled here — calculate carry forward separately and adjust the allowance.
What's the lifetime allowance?
Abolished from 6 April 2024. Replaced with two new allowances: Lump Sum Allowance (£268,275 max tax-free lump sum) and Lump Sum and Death Benefit Allowance (£1,073,100 across all pensions). The annual allowance still applies to contributions in working life.