New figures revealing teachers have been paid more than half a million dollars in advances to cover Novopay pay system errors have added to calls from schools for an urgent independent review of the system.
Principals' Federation president Phil Harding says the figures, which indicate almost 8000 people have been underpaid or not paid at all, while more than 6000 have been overpaid since the Novopay system started, are probably conservative.
Mr Harding says the errors have led principals to take the unusual step of asking the Auditor-General to conduct an urgent review of the system.
"We now totally lack confidence in this software and we want an independent review long before the signalled review for April, that's too far away," he told Radio New Zealand.
"We need to know now, `Is this company and is this software going to come good?' Because we cannot continue like this."
Labour's Acting Education spokesman Chris Hipkins, who obtained the figures from Associate Education Minister Craig Foss, said $560,000 had been advanced by schools to cover Novopay's mistakes.
There had only been 281 manual payments to correct faults processed, despite assurances wrong payments could be corrected manually, he said.
There had been 15,000 unanswered calls to the Novopay call centre.
The pay system was expected to cost taxpayers $189.5 million over 10 years, Mr Hipkins said.