School admin staff are resigning due to stress over the Novopay pay system as secondary teachers prepare to take legal action.
A survey of 1155 school principals shows 23 staff have resigned since the error-prone pay system was introduced, while many more are considering following them, Principals Federation president Philip Harding says.
"This is a distressing finding," Mr Harding said.
"We can reasonably assume that our survey respondents are representative of all schools. We can therefore extrapolate from the data that there could be as many as 50 resignations across the country and many more at breaking point."
The survey also showed the proportion of schools experiencing issues had gone up from 86 percent in October to 96 percent.
Other results for the 1155 respondents showed 25,585 staff were incorrectly paid in the last pay period, and 55.5 percent of schools paid staff from their own school funds, Mr Harding said.
"We cannot stand by and watch schools lose highly valuable staff through the stress of trying to make a completely dysfunctional Novopay system behave rationally."
The Post Primary Teachers Association announced on Tuesday it would allow its 18,000 members take legal action for those left hurt, humiliated or out of pocket by ongoing payroll problems.
"Members' patience and goodwill has all but run out. Continued Novopay errors mean schools, students, principals and administration staff are at the end of their tether," PPTA president Angela Roberts said.
The PPTA said discussions were under way with lawyers.
Talent2, the company that supplies Novopay, released the first of three software upgrades last weekend, with others to follow in March and April.
A ministerial inquiry is investigating all aspects of the error-ridden system, which has caused strife since it was rolled out in August.