Ponsonby Intermediate principal Wim Boxen said the school offered a one-off donation to parents whose children's phones were stolen.
He declined to name the school's insurer but said the school would probably be changing insurance companies.
A spokesman for the Insurance and Savings Ombudsman, Iain Opray, said the phones might not have been covered because the school took every reasonable care to protect the devices and wasn't liable for the loss.
Opray said most cases of phones stolen from schools would come under parents' home and contents policies.
Gary De Witt's son Harry is in year seven at Ponsonby Intermediate, and had owned his phone for only a few weeks before it was taken.
He said Ponsonby Intermediate encouraged students to hand mobile phones to teachers to be put in a teacher's cupboard for safe-keeping.
"I think they put their phones in a locker for safety so they don't get pinched out of kids' bags."
De Witt said the theft would have been covered under his contents insurance but there was little point claiming for it because of the cost of his excess.
Unless the phone was a "flashy one" making a claim was a bit pointless, he said.
He declined the offer of the donation from the school but said it was probably given to parents who asked for it and needed it.
Ponsonby Intermediate encourages students to take electronics to aid learning. It held a "Bring Your Own Device" week at the beginning of April.
In the permission slip sent home, the school asked parents to agree that "all devices brought to school are my child's responsibility and the insurance for the device is my responsibility".
