The Child Support Agency has come under fire from a public spending watchdog for failing to take action against parents who do not pay maintenance.
In Northern Ireland £71m is owed in unpaid maintenance
A report by the Public Accounts Committee at Stormont said the amount owed in Northern Ireland is £71m.
But only 12 people were successfully prosecuted for non-payment of child support during the first nine months of this financial year.
PAC chairman John O'Dowd said children were being let down.
"We have urged that the CSA does go out after the money, that they set higher targets - £1.5m of debt collection next year is not acceptable," he said.
There are thousands of people avoiding paying maintenance on the CSA's books, but a third of absent parents paid nothing.
The agency is working with the judiciary but is handling 9,500 cases where the non-resident parent failed to make full and regular payment, affecting around 12,600 children.
The PAC said it was dismayed that the Agency considered 58% of its £71m debt to be uncollectable and warned it had set recovery targets which were not ambitious enough.
"It is the committee's view that this is sending out the message that if someone is assessed by the Agency for child maintenance they do not have to pay because it is unlikely that the Agency will collect it," it said.
Administrative costs are eating up 88p out of every pound collected in NI, compared to 57p in the Great Britain equivalent.
The Department for Social Development (DSD) told the committee there were more parents on benefits in Northern Ireland and wage levels were 85% of those in Great Britain, decreasing the sums collected.
Inadequate and poorly performing IT systems have also been blamed for many of the problems, including 15-year-old debt.