kitt3n - even if your ex only has to pay you $14 a month, its something towards the childs upbringing. had you decided not to go ahead with pursuing that measley amount, you'd have lost a hell of a lot more than that from the government... it really is worth it

as for the ex that doesn't declare his earnings, the government (CSA,c'link, ATO) don't know these things unless they're pointed out, so do a tip off! it's not "dobbing", it's not "un-Australian" - it's the right thing to do. why should he get away with not paying taxes (if nothing else) - the rest of us have to do it!!! and you can guarantee he makes use of goverment funded services in his everyday life (medicare etc)...
Unfortunately you cant just do a "tip off". I tried to go through this, but in order to do so you have to fill out a massive form, and you HAVE TO declare that you have informed the other party that you have submitted this info to CSA!

So in order to tip off CSA, you have to let the non paying, tax evading scum know that you are doing so.

You can only imagine the hell that this would have brought on me.

I just hope karma comes his way.