pension contributions higher rate earner

Hi I am a higher rate earner and have been for several years. I have only recently been completing SA returns because of additional income and just found out that I can claim higher rate tax relief on my pension contributions which are deducted from my gross pay through my SA return. . My question is can I go back and claim for the higher rate relief for earlier years and if so how far back and how do I go about doing so? Many thanks in advance

Hi ,
 

You can still amend the return for 2023. For earlier years, you will need to send in a letter giving details of the amounts paid for each year. The furthest back we can go is to year ended 5 April 2021 as earlier years are now out of date . Thank you .