Parents in the wider Bay of Plenty region pay more than $6 million a year towards their children's education.
New Ministry of Education data shows parents paid $6,054,168 in school donations in the Bay of Plenty, Rotorua and Taupo region in 2014. Schools gained a further $5,541,422 through fundraising.
The previous year, schools received $6,535,379 in donations and $6,971,713 in fundraising.
Nationwide, donations and fundraising reached $161.6m, according to Ministry of Education figures.
Tauranga Boys' College principal Robert Mangan said the school asked for a donation of $120 per student. That amount was reduced for siblings.
Read more: Family apologises for over booking DoC hut
The figure had been the same for at least the past decade.
He said parents might have been less inclined to pay the donation when they had to start paying for school buses early last year.
However, he believed willingness to pay donations was on the rise again as parents were happy with the quality of education and understood the importance of the donation to the school.
Those donations were essential for enhancing the level of service the school could provide for students.
Mr Mangan said the money from donations went towards IT and additional equipment for areas such as music and physical education.
There was no penalty for those students whose parents could not afford the donation.
Maungatapu School principal Sue Horne said the school asked for $60 per pupil each year as a school donation and an additional $12 to go towards photocopying costs.
Ms Horne said donations went towards providing resources for the children to support their learning.
The school let parents know the donation was not compulsory but many, many parents liked to put something towards it.
"They don't always have to ... front up and pay the whole $60 straight up. We're just grateful for whatever we can get really."
The donations allowed the school to provide a few extras for students, which would otherwise have to be funded out of the school's operational grant, Ms Horne said, although it had become harder for parents to pay donations as the cost of living had increased.
She said some parents were struggling to put food on the table and the donation needed to be a second priority.
However, many parents this year had paid the donation at the time of enrolling their child.
"A lot of parents like to be able to pay their donations and they will go without other things in order to do that, which we are aware of."
Tauranga Budget Advisory Service manager Diane Bruin said the service worked with parents on allocating funds in their budget for school donations.
"What a lot of them do is start automatic payments. Depending on how many children there are. That may be $10 a week.
"Those work really well."
Mrs Bruin said at this time of year, the service saw many families that got into trouble and needed help with finance for schooling.
She said schools were pretty understanding about that. Many low decile schools in the area also capped the amount for donations for families with more than one child at the school.
New Zealand Principals' Federation national president Iain Taylor said money from donations paid for swimming programmes, IT devices, school signage and beautification of grounds and buildings.
It also covered security systems, fencing, sports equipment, art and craft materials, food, textile and engineering technology, and subsidised camps and trips.
"It is these programmes that create positive memories for kids. Schools do not spend money on unnecessary activities. These activities are essential for a child to grow up as an independent, self-sufficient, responsible participating citizen with a sense of respect for society and the environment and for the property of others."
Mr Taylor said many schools had become reliant on school donations because funding levels were not covering basic operation costs, especially in higher decile schools.
Lower decile schools sometimes did not even ask for donations because they knew the families in their communities could hardly meet survival needs of families, let alone school donations.
Mr Taylor said principals of those schools sometimes had to look to charitable trusts, corporate sponsorship and local businesses for funding.
Those businesses were then marketed directly to the children and their parents, which could have detrimental effects.
The Government could also withdraw funding from those schools, undermining every child's right to a free quality public education, said Mr Taylor.
Most schools had systems in place to ensure no child was excluded because they could not pay a fee.
"That doesn't mean to say there is not financial pressure on schools that have to support greater numbers of children especially in areas of high poverty," he said.
Last month, Labour's Education spokesperson Chris Hipkins branded "free" education a joke.
"Parents and other donors are propping up our schools to the tune of $1 billion with the country's wealthiest schools receiving the bulk of the money."
But Education Minister Hekia Parata said parents contributed just $1.80 for every $100 spent by the taxpayer on education.
By the numbers:
* Parents paid $6,054,168 in school donations in the Bay of Plenty, Rotorua and Taupo region in 2014. Schools gained a further $5,541,422 through fundraising.
* The previous year, schools received $6,535,379 in donations and $6,971,713 in fundraising.