Self Assessment - Charity Donations for years prior to 2021-22 tax year

Hello, please can somebody advise? I have submitted a self assessment tax return for the first time for 21-22. I have put my charity donations which are gift aided for this year and have found out that I get tax relief as I am a higher tax rate payer. I have been a higher tax rate payer since 2019 and understand that I should be able to get the same tax relief on my gift aided charity donations for tax years 19-20 and 20-21 as well. However on the 21-22 submission I could not see where I could enter in the previous year's donations. Please can somebody tell me how to get the tax ‘overpayment relief’ on these previous year's donations? Thank you in advance.

Hi,
 

If you were not due to complete a return for the previous years please contact our helpline and we can update your record. See link: Income Tax: general enquiries    . Thank you.