Claim tax relief on personally contributed retirement (SIPP)

Hi, I contributed £20,000 into ii (Interactive Investor) SIPP. They added £5,000 back into my ii account. Now I am filling self-assessment form and there is a section for SIPP. I am confused whether I should put £25,000 in that section or £20,000. Another question would be, how much would be my total tax refund for this £20,000. Given that ii gave me £5,000 back, how much more will I get back from HMRC and in what account? I know this is a naive question, but help would be appreciated. I am in additional rate (45% tax bracket).

Hi Rajwinder Singh,
When declaring your SIPP pension on your return, you would enter the grossed-up amount - in this case, £25,000.
For advice on your expected refund, we would need more information - contact us by webchat or phone here:
Self Assessment: general enquiries
Thank you.