Correct taxable income for high earner child benefit charge

What is the correct approach to prevent being effectively taxed / charged twice for the same taxable benefits when it comes to the high income child benefit charge? My current tax code is 1135L, reduced from 1257L for the last two tax years to account for 1,220 worth of taxable benefits that I receive. Therefore, the amount on my P60 already takes into account the value of my taxable benefits. However, when completing my tax return, if I include the details of those taxable benefits as requested, it automatically adjusts my total taxable income upwards which affects the amount I owe HMRC. Please advise.

Hi ,
 

The taxable benefits are included in the code to deduct tax due. On the Self Assessment you will still need to inlcude the taxable benfits as shown on your P11d and will get the credit for the tax deducted at source as shown on your P45/P60.  Thank you .