Child Benefit and higher income - what time period do we have pay for?

[sunface]

hoping someone can please help. i've (probably stupidly in hindsight) still been claiming Child Benefit since the higher income charge was brought in last year and am going to do the online self assessment for my partner tonight (he earns in region of £55K) but scaring myself witless at what we might need to pay back as we can't afford to pay a lump sum. Can anyone tell me if i am submitted a self assessement if it covers 2012/13 tax year? and if so, do they look at CB claimed since the higher income change was brought in (ie Jan 2013) or is it from April 2012? Thank you anyone for any help

Am in same position, have 3 kids, husband earns similar amount - we have paid back around £330 I think - can remember exactly as we paid it a couple if weeks ago

*cant remember exactly

If you've made any charitable donations that may lessen what you have to pay back. When dh did ours he found HMRC owed us - even with the Child benefit charge levied! Next year we'll owe them but meh