But schools can solicit donations for voluntary activities such as cultural and sport trips.
Two-thirds of principals who responded to the survey reported a reduction in school finances following the policy change, some saying they couldn't afford to be compliant with the guidelines, and other had chosen to ignore them.
Office of the Auditor-General communications adviser Mike Heine said during annual school audits of the 2013 financial year information was collected from all secondary schools to examine what parents were paying to schools.
That was to determine whether there was an issue of non-compliance and whether the Auditor-General needed to take further action on the issue.
"That work is ongoing.
"We will be analysing the results of this special exercise to determine whether to carry out further work in this area in the future," Heine said.
The principals' council said its anonymous survey showed some schools clearly felt they had no choice but risk being publicly shamed by the Auditor-General for failing to meet the legal requirements.
Ministry of Education head of sector enablement and support Katrina Casey said every year there were a "relatively small" number of complaints about donations.
When reminded of their obligations the vast majority of schools amended financial demands.
Complaints from parents as well as information from other government agencies about failure to stick to legal guidelines were investigated, and where warranted, followed up with schools.
"Our goal is to support schools so that parents can rely on their ability to deliver educational outcomes as legally required," she said.
Heine said if auditors found a school was collecting payments from parents that did not comply with the guidelines it would be raised in the auditor's management letter to the board.
The school would be earmarked to check it was complying in the following year's audit.
