"The [existing] School Donation tops up the school's day-to-day operational costs in areas of classroom supplies and equipment not fully funded by the Government," it says.
"Funds collected through Annual Giving will be put toward more substantial costs such as new buildings, including the new Science block and a Performing Arts Centre, other facilities and the employment of specialist teachers."
The new "Annual Giving" donations will go to the Mount Albert Grammar School Foundation. Charities Office records show that the foundation's income has risen from $83,079 in the first year on record, 2013, to $721,678 in the year to March this year.
Other large schools also have foundations. Auckland Grammar has seven registered charities and its Auckland Grammar School Foundation Trust raised $1.6 million last year.
But Post Primary Teachers Association Principals Council chair James Morris said Mt Albert's approach was unusually explicit about inadequate state funding.
"I've never heard of an approach like this before," he said.
"Philosophically it's no different from asking for annual donations, except it steps it up to a higher level of marketing and expectation from the parents."
He said the move raised concerns about equity because many schools would not be able to raise anything like the sums raised by Mt Albert Grammar or Auckland Grammar.
Wellington-based charities lawyer Sue Barker said it was now "quite common" for schools to have fundraising foundations, even though the 33 per cent tax rebate for donations can be claimed for donations given directly to schools as well as to their charitable trusts.
"It might just be that they want to keep [fundraising] separate and keep a separate fund," she said.
However, she said the Inland Revenue Department issued an update last year which stopped a "rort" in which some private schools had been describing their fees as "donations" so that parents could claim the rebate.
"I'm told they are working on another one that will be extended to state schools," she said.
"The Education Act gives every student the right to a free education, so if it [a donation] is for a general fund, that's how you can get a tax credit for donations to state schools, because the state offers free education.
"But even then you have to be careful that it is not actually a fee."
Mt Albert Grammar is a special case because the Ministry of Education has told it to reduce students from outside its zone rather than funding new buildings. The ministry said in July that 23 per cent of the school's students came from outside the zone. Drumm said the figure was "less than 20 per cent and falling".
New Zealand's biggest school, Rangitoto College, does not have a charitable foundation. Its only registered charity is the Rangitoto College PTA Charitable Trust, which recorded an income of only $4936 in the year to March.
