The personal allowance is set by the UK government each year and may vary depending on an individual's circumstances.

For the tax year 2022/23, the standard personal allowance is £12,570. This means that individuals can earn up to £12,570 in income during the tax year before they have to pay any income tax. The personal allowance is deducted from an individual's gross income before income tax is calculated.

It's important to note that the personal allowance may be reduced for individuals with higher incomes. For example, for every £2 of income above £100,000, an individual's personal allowance is reduced by £1. This means that an individual with income of £125,000 or more will not be entitled to a personal allowance.

There are also special rules for individuals who are blind or partially sighted, as well as those who are entitled to the married couple's allowance or the blind person's allowance.

Overall, the personal allowance is an important part of the UK tax system and helps to ensure that individuals are only taxed on their earnings above a certain threshold, allowing them to keep more of their hard-earned income.