£100k tax trap calculator 2026/27
See the Personal Allowance lost above £100,000 and how pension contributions or Gift Aid may change adjusted net income.
How the £100k tax trap estimate works
The £100k tool shows how adjusted net income above £100,000 withdraws Personal Allowance and illustrates the effect of relief-at-source pension and Gift Aid entries. It is not a recommendation to make a contribution.
Rules checked
Read the checking method
What the result includes
- Personal Allowance remaining after the taper
- Grossing up of net relief-at-source entries
- An illustrative before-and-after Income Tax difference
What to have ready
- All taxable income, including benefits, savings and dividends
- Net relief-at-source pension payments
- Net Gift Aid donations and the correct tax year
Questions about £100k tax trap
Why is the effective rate so high in this band?
Income is taxed and also removes £1 of Personal Allowance for every £2 above £100,000, causing more existing income to become taxable.
Will every pension contribution reduce adjusted net income?
The treatment depends on the scheme method. Salary sacrifice and net-pay contributions may already be reflected in pay, while relief-at-source contributions are normally grossed up.
About this estimate
Adjusted net income can include benefits, savings, dividends and other income. Pension tax relief method and annual-allowance limits need separate checks.