Wow, that's huge they can do that... Without warning?

I'd be drawing out all my money as soon as it landed in my account
Maybe I shouldnt respond to these threads but really?

Yes, how terrible to force parents to be responsible when they have chosen not to do so voluntarily. Child support sets reasonable amounts to be paid regularly, sure they might seem unreasonable when hit all at once but maybe if people were just as concerned and just as accountable for being in child support arrears as rent arrears then there wouldnt be financially significant debts in the first place.

I guess tough luck if the other parent needed the child support for rent themself in the first place?