do childcare vouchers affect csa payments?

[fragglerocker]

Ok, might be an odd question but was just wondering. OH pays csa for one of his kids by an ex partner and he has just enquired about childcare vouchers at his work for our DS. Now I don't 100% understand how these work but what I sort of know is he sacrifices part of his wage for vouchers and he doesn't pay tax on this amount. Am I right? Now will this affect how much csa he pays as he will be paying less tax on his wages? I don't know how they work out csa payments, is it on his taxable earnings? There's probably a very simple answer but just wanted to check! TIA

At the moment the csa payment will be calculated upon the amount left after he takes the vouchers, but when they change the system (2012 sometime) they will be worked as a percentage of the gross wage, so before tax/pension/salary sacrifice etc.

Thanks. i will get him to ring csa when we get the vouchers sorted and they can change the payments. I'm sure they won't rush though!