Government figures show serious absenteeism from school has dropped in the past two years, but senior secondary students and children in Northland still have the worst attendance.
More than 20% of students in those groups missed at least one day of school a week in the second term last year.
Secondary principals say their figure is due to extra-curricular activities and because some students skip classes not needed for their NCEA.
Tai Tokerau Primary Principals Association president David Rogers, says transience is the biggest factor.
Nationally, 12.8% of students missed more than one day per week of term two, down from 21% two years ago.
Principals say the improvement is because of electronic roll-keeping and texting parents.