High Child Benefit Charge - How to fill out the self assessment?!

[WinterWeather1]

I'm hoping you lot will be able to help me as I have already managed to stump 2 accountants today with this.
My husband needs to do a self assessment for the child benefit that we claim. From reading several forum posts and Martin Lewis, I am of the understanding that pension contributions (DH is defined benefit pension) can be deducted from the gross salary to get the adjusted salary.
This would make a significant difference to how much we need to pay back.
The issue I am having is how I put this information on the self assessment form. I put in the full gross salary as it appears on his P60 on the employment page but the only place I can see to put the pension is for claiming back tax relief on it. This then causes the system to think it owes us nearly £900 which is incorrect as I am pretty sure DH already gets tax relief on his pension.
Can anyone give me a dummies guide on how to fill out the form so that we pay the correct amount?
The childcare tax calculator makes it seem so easy but the form is so confusing!

Right, I have just got off the phone with HMRC. 8am is obviously the time to call them as no wait! I thought I would update for anyone else who may be confused!
We went round the houses with tax relief again and it took a while for them to understand what I meant about adjusted income and not tax relief as I know DH already gets that. We got there eventually and they said that all I had to do was minus the net pension contributions off the p60 salary and enter that into the salary box on the self assessment. Then put in the comments section what I had done and why otherwise they would automatically change it back to the P60 wage. This would then give the correct repayment amount at the end.

Agree re the 8am call, I just did the same oddly enough @WinterWeather1! Mine was fine too but a diff query to yours I know. Glad you are sorted. I feel more relieved too (I was doing the right thing in my case) so glad all is good.

@goingpearshaped well I am back on with them again as it was then saying we were due a £1400 refund! Gosh, why is this so difficult!!

Aggh, @WinterWeather1, good luck. I hate this stuff, I have lost sleep over it in the past, it is a huge anxiety trigger. I hope you get sorted :)

So HMRC version 2 said to submit tax return with the correct figures as shown on the p60 but put adjusted income in the comments section. I then need to wait 72 hours and call them back as they will then be able to see the tax return and advise further on how to get the correct amount to show. What a palaver!

[quote WinterWeather1]@goingpearshaped well I am back on with them again as it was then saying we were due a £1400 refund! Gosh, why is this so difficult!![/quote]
It is possible he has been taxed by his employer on his whole gross salary of course, rather than his after pension conts salary. Can you do the calculations yourself?

@titchy HMRC said he gets taxed after his pension is taken out so he is already getting the tax relief he is due.
I think is employer must pay in an odd way to stump so many people as surely there are thousands who have to do this to pay the higher rate childcare charge.