At what salary level does the reduction of personal allowance begin?

The correct salary level at which the reduction of personal allowance begins is £100,000. In the UK's tax system, individuals are entitled to a personal allowance, which is an amount of income that can be earned tax-free. However, this allowance starts to be reduced when an individual's income exceeds £100,000. Specifically, for every £2 of income over this threshold, the personal allowance is reduced by £1, until it eventually phases out completely once income reaches £125,140.

This mechanism is designed to gradually withdraw the benefit of the tax-free personal allowance, ensuring that higher earners contribute more towards income tax. Understanding this threshold is critical for effective tax planning, as exceeding it can lead to a significant increase in tax liability.