Parents who remove their children from classes to take cheap flights and holidays are part of the reason 62,000 Kiwi kids miss school each week.
Principals say rich and poor families are pulling their youngsters from school for travel - although an education expert has defended such trips, saying they can teach as much as school.
Schools say many other excuses for absence from class don't hold water. But poverty-related reasons for non-attendance, such as babysitting younger siblings while parents work, are harder to address.
Findings from a Ministry of Education survey showed that about 62,000 students were absent from school for all or part of a day during the survey week, and 15,000 were unjustifiably absent.
The survey gathered information on student attendance over a week in June last year from 2166 state and state-integrated schools.
Allan Vester, chairman of the NZ Secondary Principals Council and head of Edgewater College in Pakuranga, said schools often referred to "parent-condoned truancy" - most harmful when it was repeated every week or fortnight.
"If you ask parents, 'Is being at school really important?' they will always say it is. But there are things in their family life that seem to be more urgent and more important than being at school."
Previous ministry reports have said parents taking their children from school to take advantage of cheap flights contribute to truancy.
Cheap flights are more widely available outside school holidays.
In Britain, the Government has warned that taking such holidays without permission could result in parents being fined 100 ($192).
Mr Vester said about four families approached his school asking to take early holidays before each break, and principals could do little because "parents are clearly going".
"We send a letter saying they need to catch up when they return and take what work they can. There's not a lot of point saying, 'No, you can't go'," Mr Vester said.
The practice occurred at both ends of the social spectrum.
"It's a problem for parents needing to get a flight a bit cheaper so they go early ... At the other end, it's parents who have time-shared ski apartments and such things."
Auckland University educationist Professor Peter O'Connor said such trips could benefit a child's education.
The real issue was habitually missing school.
"The opportunity to take your child to Florence when they are 9 or 10 years old and take them out of school for a week, I'd suggest that can have significant impacts on learning, for the positive."
This year, the Government created a new Attendance Service, with extra funding, and reduced the number of agencies contracted to keep children in school.
The principal of Bairds Mainfreight Primary School in Otara, Alan Lyth, said the new system had not worked as well for his school.
A hard core of families frequently kept children away unnecessarily.
"Some of the reasons just don't hold any water. Nobody seems to be able to get on top of them. ... People seem to know that so long as the kids get back to school for a couple of days, that's going to get people off their backs," Mr Lyth said.
Robin Staples, who is director of Southern Cross Campus, a decile 1 Year 1-13 school in Mangere, said older children sometimes missed school to help babysit or step in for parents who were working long hours.
Others came to school tired after working late to support their family.
"We try to counsel parents not to allow that, but [given] the reality that families find themselves in in terms of putting food on the table, they have to rationalise those things."
The Education Act requires students to attend each school day. But a principal may allow an absence for no more than five school days.
The ministry's group manager of education, curriculum and performance, Marilyn Scott, said it was unacceptable for parents to take children out of school during term time for a holiday.
She said boards of trustees could prosecute parents for their children's non-attendance, but this should be a last resort.
Trip diary makes the holiday work
When Louise Richardson took her daughter Issey out of school for a holiday in Hong Kong last year she knew the trip could not be all play.
Issey, then 11, missed a week of classes. Staff at Balmoral Intermediate agreed to the trip, but required her to keep a journal.
"I was conscious of the need to make sure that it was a learning experience, as well as fun," said Ms Richardson.
"Most of the schools make it clear that it's a serious thing ... so you feel that you've got to go in there and put a pretty good case.
"They tend to be quite understanding, but they are conscious that kids can miss out on such a lot. And I agree - it's not something I would ever do unless it was unavoidable."