Child benefit charge more than actually paid

I'm in the process of completing my self assessment in respect of the child benefit tax only and the calculation for tax is more than the child benefit paid. The issue seems to be that the personal allowance used in HMRCs calculation is lower than my actual tax code. My tax code is 1288L (reflecting the working from home allowance) but the standard allowance of 1257 has been used. How can I correct for this in my tax return?

Hi,
For advice on your query, you will need to contact our Income Tax team usinge the link below.
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Thank you.

Not HMRC...the personal allowance will always show as that where entitled to £12570, it doesnt increase for expenses, they are not personal allowance they are separate deductions. You need to enter the working from home claim amount as a fixed employment expense on the return, and it would then deduct the amount claimed from taxable salary, reducing the amount liable to tax. If youve done that already (check P.60 figure to assessable figure in HMRC calculation, difference should be the amount) and the amount due is still more than the child benefit received then there is something else affecting the PAYE (i.e. PAYE is underpaid for some reason).

Hi Clive. Thanks for your incredibly helpful response. My return is now correct?