The union representing secondary school teachers is to take legal action over Novopay.
The payroll system, worth $100 million over 10 years, has been plagued with thousands of errors since it was introduced in August last year, with underpayments, overpayments or no payments at all to some teaching staff.
PPTA president Angela Roberts said on Tuesday after six months of continual problems, teachers and school staff have run out of patience and goodwill.
Ms Roberts said they are frustrated by a lack of urgency from the Ministry of Education and are looking at a number of avenues for collective legal action.
Teachers and other staff are to seek compensation for the hurt, humiliation and financial suffering caused by Novopay, she said.
Union lawyers are discussing exactly whom could be the target of legal action, as normally a case would be against the school boards which employ the teachers.
However in this case, the boards are just as frustrated as their employees.
The PPTA is inviting individual teachers to take part in the proposed action.
Admin staff resign
The Principals' Federation says 23 administration staff have resigned as a result of dealing with Novopay.
The federation says a survey released on Tuesday of about half its members found that the proportion of schools experiencing problems has jumped to 96%.
President Philip Harding said on Tuesday the situation is a "complete nightmare" for administration staff dealing with the problems and they are under too much stress.
"That's not what they came into the school for. They looked for a job that could fit with their lifestyle and their families, and they're finding that the stress from Novopay and the heartache and the time that it's taking is just too great.
"And often it means that work that you've been planning to get on to, you can't do."