Dunne said the proposed changes to the child-support formula would apply from April 2013, and changes to payment, penalty and debt rules would be introduced the next year. It would mean that some parents would receive lower payments but it would be a "fairer" system.
Union of Fathers president Allan Harvey welcomed the overhaul but said changes could go further. Fourteen per cent of nights in one parent's care should qualify as "shared care" status - the equivalent of every second weekend.
. "It's not usual for children to be in one parent's care every weekend." Harvey also said family household income, when one of the former partners took a new partner, should be taken into consideration, rather than an individual parent's.
Dunne, in announcing the proposed changes at a United Future conference in Wellington, said changes needed to be made to the dated system to reflect the views of about 2000 public submissions.
But the proposals could not be expected to please everyone, he said.
"On something as contentious and as emotionally charged as child support, which only ever comes into people's lives when their relationship has broken down, it is not about trying to please people.
"It is about creating a system that people feel is fundamentally fair and, crucially, that they feel is for the benefit of their children."
Harvey said the system should encourage private agreements between parties, as people stuck to them.