The Ministry of Education says Novopay is more at fault than schools in the ongoing saga over workers' pay.
A briefing report sent to the minister in charge of Novopay, Steven Joyce, said the payroll system's software is sound and the problems were caused by teachers sending information by email rather than using online forms.
It said there are not enough Novopay personnel to put information from the emails into the system, which had led to delays and mistakes in payments.
The document said the Novopay computer system was not user friendly, resulting in an unexpected number of teachers submitting information by email.
An education union, the NZEI, has criticised the blame put on schools.
But the ministry says while some schools are responsible for some data entry mistakes, these are far outnumbered by errors that occur with Novopay itself.
The briefing report says the payroll system may take another 18 to 24 months to fix.
