Timaru parents owe more than $7.4 million in child support payments with almost two-thirds being debt from penalties.
Figures from Inland Revenue show $4.9m is currently outstanding in child support penalties and $2.5m from child support payments.
However, from April 2014 the Government will be making changes to child support laws. These include relaxing penalty write-offs and reducing interest on overdue child support.
Union of Fathers national president Allan Harvey said the changes would greatly help fathers who were paying child support.
At the moment the system is set up to make the debt so large fathers are avoiding the payments, rather than dealing with them, he said.
"When systems are like that, you do not get good compliance, you get massive non-compliance."
Mr Harvey said while all fathers they work with have their children's best interests at heart, 90 per cent to 95 per cent of the debt was incurred by men.
Timaru Budget Advisory Trust co-ordinator Don Macfarlane said overdue child support payments were a "big festering sore in New Zealand".
He said the service often helps parents who have not received child support payments to budget and liaise with Inland Revenue.
Inland Revenue said it had collected almost 90 per cent of child support payments owing since the child support scheme began in 1992.
"The way we manage a liable parent's debt depends on the type and size of the amount owed and how compliant the parent is."
- © Fairfax NZ News