Tax on savings interest

How much interest on my savings can I have before I pay tax on it? My only income is my state pension and this is £15,000 top regards

You need to register for Self-Assessment if your income from savings and investments is over £10,000 in the financial year.

You can find further information here:

https://www.gov.uk/check-if-you-need-tax-return

If you earn interest over your allowance but under £10,000 and are employed or receive a pension, HMRC will change your tax code so you pay the tax due automatically.

The code for the current year will be based on how much interest you had in the previous year.

Further information can be found here: https://www.gov.uk/apply-tax-free-interest-on-savings