Child benefit high income charge

[hopethishelps12]

First time figuring out the self assessment and HMRC scares me (which is why I am PAYE and not freelance in the first place, but there we go). I claimed for the whole 2024/2025 tax year (£1,331.00)

Earned £70k (per my P60), but the calculation is saying I only owe back £505. Whereas I thought it would be more like £665.50 (ie, 50%).

What I want to know is, if I've done something wrong and underpay, what's the worst that can happen? Will they just want the money owed back, or could it be a fine too?

Perhaps I should just pay someone for the first year, but £150+ to get so little back anyway is a bit difficult to swallow. So any help appreciated!

It’s self assessment, so the process is that HMRC will accept the numbers unless they undertake an enquiry into your Return (possible, but unlikely). It could be that your PAYE coding had collected more tax than you thought, or that you included something else which brought your liability down - did you include any charity contributions or something?
At the end of the day, your number is so similar to HMRC’s that I really wouldn’t worry.

I think that pension contributions are taken off the gross figure. Would that account for the difference?

You've either overpaid your tax slightly over the course of the year (any bonuses?) Or you have some deductions (pension?)

Ah I did have a bonus - so that could explain it.

Thanks all for the reassurance, I'm just going to submit it and hope i've got it right!