First ever pension contribution

I have never had a pension before and am about to open my very first pension in the form of a SIPP. Two questions come to mind: 1. I will open my SIPP on 1 January 2024. Is my maximum contribution a) the lower of £60,000 and my relevant earnings for the full tax year 2023/24 or b) the lower of £60,000 and my relevant earnings for the period 1 January 2024 to 5 April 2024? 2. I understand that I can only backdate my pension contributions for 3 years and then only if you are in a pension scheme during the year you are backdating to. In my above example therefore, given that I have never participated in a pension scheme before, I do not have any ability to backdate / carry backwards my pension contribution. Is this correct? Thank you.

Hi

In order to qualify for relief, the maximum is limited to your relevant earnings for the tax year.
The £60k limit is to avoid a pension tax charge. You cannot backdate your contributions as relief is only due in the tax year the payment is made.
What you may be thinking of is the unused allowance form previous year to avoid the pension tax charge.
Further guidance is at Tax on your private pension contributions

Thank you