Pension contributions being taxed on self assessment?

Hi, I am completing a self assessment tax return due to meeting the threshold to repay child benefit however when I perform the calculation, it says I owe an additional £2k tax. My taxable income is calculated as gross salary minus personal allowance. Do my pension contributions via employment not need to be removed from this figure too to calculate taxable income? If the calculation is correct then I appear to have to repay 40% higher rate tax on the £4k pension contributions Thank

Hi Gavin,
If the pension contributions are taken from your wage before the tax is calculated then this will be taken into account on your P60 which will show the taxable pay.
Thank you.