Getting tax relief (pension contributions) from previous years

Hello I will be making the max. pension contribution (re:tax relief) of £40K this tax year. I have been advised that I can actually 'top up' my contributions from the previous 3 years (in no previous year did I contribute more than £15K) and claim tax relief on those contributions. How do I do this? Do I need to amend my tax returns from previous years (is this even possible)? Thank you

Hi Rachael Hawken,

You do not need to amend the return.
Further guidance on pensions is at:
Pension savings — tax charges (Self Assessment helpsheet HS345)

Thank you.