After 18 months of Novopay problems, a teachers' union says the payment system is a mess and needs to be fixed.
The Educational Institute, which represents teaching and support staff, says thousands of hours are wasted untangling payroll problems, and people are left unable to pay their bills.
It says of the 30 schools it surveyed, 80 percent reported serious flaws with Novopay, including problems with non-payment, overpayment, tax and holiday pay.
Institute spokesperson Andrew Casidy says the Government needs to sort out the mess that has been continuing since Novopay's launch in September 2012.
He says the matter is now affecting student learning and the strain and frustration inside schools is obvious.