Self Assessment and P11D / Child Benefit

Hello, I complete a Self Assessment due to the money i need to pay back in relation to Child Benefit. Part of the Self Assessment asks if i have any PMI and if so submit the amount from P11D. I have this benefit so include this amount on Self Assessment which increases the amount on my tax return i need to pay. My question is... my tax code was on a level that was associated with a Benefit In Kind. With me also adding the amount from the P11D in Self Assessment, am i not paying tax on this benefit twice? once from my monthly tax (through tax code) and once in a lump sum through Self Assessment? Many Thanks

Hi,
No, it will not be taxed twice as on the Self Assessment you declare the tax deducted at source by your employer which will include the tax collected on the benefit in kind in your tax code. 
Thank you.