Westbrook School principal Colin Watkins said principals and Boards of Trustees had been put in a difficult position.
"Principals being forced to consider sacking hardworking support staff while tax cuts are given is totally immoral. If there is a little fat in the budget it needs to go to core services - health, education and welfare."
He said he needed every single one of his 18 support staff so would not be cutting their hours, instead making up the money elsewhere.
"There is more demand now than ever before for support staff. We are seeing dyslexia growing, fetal alcohol syndrome growing - these children need all the help we can give them.
"We've increased our parent donation by $5, recognising our donations are at the lower end already. Other than that, we are just finding other ways to make ends meet."
He said the situation was frustrating and in his view counter-productive to the Government's aims to improve NCEA and National Standards outcomes.
St Michael's Catholic Primary School principal Shelly Fitness has cut her principal's expenses budget entirely and has reduced the staff and principal professional development budgets.
"We met as a board and had a really good discussion. We came to the decision that we would not be cutting support staff to ease the financial strain, instead making cuts in other areas.
"What it means is we have to get creative about our teachers' professional development, instead of sending them to conferences and workshops as we normally would."
Ms Fitness said the school had not increased its donation because it did not want to put any more cost on to families.
Rotorua Principals' Association president and Ngakuru School principal Grant Henderson said his school was preparing for a tight financial year.
"Ngakuru was one of the schools that received no funding under the new model and as a result we have suffered a negative gain on operation costs.
"Thankfully our roll has grown slightly above what was projected for 2017 so we will make do but it does mean we won't have enough money if any unforeseen expenses arise."
Mr Henderson feared this freeze would set a pattern that saw a continued freeze on funding.
"If schools are forced to cut costs to bridge that gap in funding, there is nothing to say the Government won't look at that and say 'hey, if they can do that once, they can keep doing it' - that's where it worries me."
John Paul College principal Patrick Walsh said the number of international students at his school provided a buffer against the funding freeze.
He believed targeted funding was generally a good idea.
"What I'm disappointed in is that it is not new money, it is money being taken out of other schools' pools to go towards the country's most vulnerable students."