A Tauranga principal has hit out at a Government offer to challenge controversial new decile ratings, calling the process "over the top" and "too time consuming".
Kaka Street Special School is one of 40 schools in Western Bay of Plenty or Tauranga given a new decile rating in November.
Decile 1 schools receive more Government funding, while decile 10 schools have fewer students from low socio-economic communities so receive less funding.
Schools could request a review if they believed the new decile did not accurately reflect the socio-economic circumstances of students.
Kaka Street principal Barrie Wickens said the school did not agree with its rating change from decile 3 to decile 4 - but had not challenged the rating as the process was too extensive.
"We looked at what needed to be done for the appeal and thought that it was over the top and too time consuming to go through with," he said.
"How extensive it is creates a barrier for schools wanting to appeal.
"One of the things we would have had to do was to look more closely at parents' employment, which we found intrusive."
Decile ratings were calculated by using student address information, combined with Census data for small geographical areas. Kaka Street is Tauranga based but also teaches satellite classes from Te Puke to Katikati.
"Financially it's not a major loss to us - $7000 a year - but that's four times the amount we get from parents," Mr Wickens said.
Ministry of Education spokeswoman Lisa Rodgers said no school would lose funding as a result of requesting a review. If a school needed help with the application, it should contact its local ministry adviser.
Of the 65 Western Bay/Tauranga City schools analysed by the Ministry of Education, 21 had their ratings reduced, while 19 had theirs increased. The rest remained the same.
Three of the districts' schools have challenged their new decile ratings.
Pukehina School principal Roger Reid has previously said the school would appeal its jump from decile 3 to 5, which would reduce hundreds of dollars in funding, plus support from charitable organisations such as KidsCan and Duffy Books.
He said some parents would not be able to afford to pay for activities the school would no longer be able to fund.
Eight hundred schools nationwide were moved to a lower decile rating in November, 784 schools moved to a higher decile rating, and 822 schools' decile ratings did not change.
The last time ratings were reviewed was after the Census in 2006.
As of April 29, 154 schools had lodged review applications with the Ministry of Education.
The ministry would not release the names of the schools but said schools would know the outcome by the end of May, when the decile rating of all schools would be updated on the ministry website.
Education Minister Hekia Parata has previously said the decile funding system was well intentioned but also complicated and "really clumsy".
"There are some significantly disadvantaged kids and families in deciles 7, 8, 9 and 10 schools, but overall the average masks that," she said.
The decile system, also described by Ms Parata as a "blunt instrument", has been re-addressed as part of a wider review of school funding.
Schools whose funding was cut after moving to a higher decile would have an 18-month transition period and additional funding to assist them.
"There are many factors that make a good school good and it's important to remember that decile funding only accounts for about 12 per cent of overall funding for schools.
"Decile ranking shouldn't be used as a measure of school quality or school performance."