In the UK you don’t pay taxes on the first 12500£ you earn in a tax year. This is the income tax allowance.
For each 2£ you earn above 100K, your income tax allowance is reduced by 1£. At 125K, your allowance reaches 0. The result is that between 100K and 125K your marginal tax rate is 60%. At 125K it goes back to 40%.
