Two boarding schools are seeking leave to appeal a court decision that could force more than 100 schools to back-pay staff for every hour they slept in student hostels for the past six years.
The Employment Court ruled in February that Iona College and Woodford House should pay staff the minimum wage for the hours they sleep in school boarding facilities.
It ordered them to back pay 11 employees for the past six years.
The Service and Food Workers Union said the decision applies to all school boarding hostels, and some school principals are worried it might also apply to over-night school camps and field trips.