Most parents with children at private schools are paying more in fees this year, despite a $35 million boost in funding by the Government last year.
The higher funding followed a nine-year period in which the Government's contribution to private schools did not increase. It is was to be spent over four years.
The Independent Schools of New Zealand says the 43 schools the organisation represents have been forced to increase fees an average of 3.5% this year.
Executive director Deborah James says that is because the funding boost is only $300 per pupil per year, which is not enough to keep up with the cost of schooling.
Without the funding increase last year, Ms James says several private schools may have had to close or integrate.
The Quality Public Education Coalition says private schools have much larger incomes than state schools and their fees should not be going up.