A parenting group says the Government needs to radically reform child and family law if it wants more parents to pay child support.
A report by Auditor-General Lyn Provost has found the amount of child support owed will grow by nearly $6 billion in eight years, if nothing is done.
She recommends a scheme that is easier to understand and new international agreements to chase up debtors living abroad.
But Fathers of New Zealand says dropping late penalties and giving parents more contact with their children, will encourage people to pay.
Revenue Minister Peter Dunne says he will put proposals to the Cabinet on child support, which will give the 20-year-old system a shake-up.