The Personal Savings Allowance is a government allowance that permits you to earn a certain amount of income from investments each year, tax-free.
Please refer to the following links for guidance:
https://www.gov.uk/income-tax-rates/current-rates-and-allowances for the current income tax rates and https://www.gov.uk/apply-tax-free-interest-on-savings for current UK savings allowances.
How much tax relief you are entitled to or tax you need to pay is dependent on your individual circumstances and subject to change so we recommend that you speak to a tax adviser.