Salary sacrifice reportable income on self assessment - Child benefit tax charge

I would like some advise regarding salary sacrifice. My P60 shows my taxable pay to be total income before salary sacrifice payments are made to my pension but my March payslip shows total taxable pay and also salary sacrifice pay which is minus my contributions. All of the research that I have done suggests that the lower sacrifice amount should be the amount that I report as income to keep a percentage of the child benefit I received for tax year 2023/24 as a method off reducing the child benefit tax charge. I have completed my self assessment with the total taxable pay on my P60 which includes my pension contributions but have not declared any pension contributions under the pension section of the self assessment. The information I am receiving from tax info websites and HMRC contradict each other, I thought the salary sacrifice reduces your taxable salary.

Hi,
Please refer to the link below for guidance:
Personal Allowances: adjusted net income
Thank you

My starred income on my P60 is showing the incorrect amount, this does not deduct my salary sacrifice pension contributions which are made before tax and shows the full salary amount. Should my P60 show the lower income amount to account for the pension deductions before tax? This would be the amount of gross income I put on my self assessment to work out the amount of child benefit charge I have to pay?

Hi,
If a salary sacrifice then this should be taken into account on the P60.
If you believe the P60 is incorrect you will need to contact your employer to review. 
Thank you.

Hi,
Income tax and capital gains tax are two entirely separate taxes.  
The 24/25 Personal allowances (12570) is only set against income.  
The 24/25 annual exempt allowance (£3000) is only set against capital gains.  
Income tax liability is calculated first, to determin the rate of tax for capital gains.  
Please note that the rates of tax for capital gains in 24/25 increased as from 30 October 2024.
Thank you.