The UK has two brutal "tax traps" — the £100k–£125,140 personal-allowance taper and the £60k–£80k Child Benefit charge — where each extra pound is taxed far above the headline rate. Paying into your pension lowers the income these are measured against. This finds exactly how much to sacrifice, and what it really costs you.
Salary sacrifice assumed: the contribution comes out before Income Tax and National Insurance, and the full amount goes into your pension. Pension money is normally locked until age 55 (rising to 57 from 2028). Most people can pay in up to £60,000 a year with tax relief (the annual allowance); contributions above that may be taxed. This is guidance, not financial advice.
These results are estimates for general information only and are not financial advice. Check every figure yourself and seek appropriate advice from a qualified professional before making any decision. Read the full disclaimer.