Policy: Some school have adopted a NetSafe inspired contract in which pupils agree to be good digital citizens and adhere to digital safety guidelines while at the school.

Half the calls received by cyber security company NetSafe about harmful online communications last year came from New Zealanders under the age of 16.

Children as young as five are bringing digital devices to school, in an effort by parents to stay in touch with their children to keep them safe, and by schools to support learning in digital classrooms.

But as young New Zealanders' digital connectedness grows, so do the risks

NetSafe chief technology officer Sean Lyons said there was confusion between children's technical ability to use devices and their ability to make good judgment calls when it came to online communications.

NetSafe had received anecdotal evidence from technology companies of young New Zealanders being coerced into producing sets of sexualised images or video of themselves by people they communicated with online.

However, the most common challenge faced by digitally connected youths was online bullying, he said.

According to NetSafe, one in five high school pupils had reported being cyberbullied.

It was up to parents, teachers and older family members to educate themselves about online risks and act as "guides".

Auckland's Diocesan School for Girls principal Heather McRae said there was no longer a clear distinction about what was a school issue to deal with and what were family issues, thanks to digital devices.

For the past three years the school had employed former police officer and online forensic specialist Brett Lee to talk to teachers, parents and pupils about the risks of being connected.

Lee had worked as a senior detective in the Queensland police with a focus on fighting online paedophilia.

Principals' Federation president Denise Torrey said children as young as five were bringing iPads and tablets to school and pupils as young as eight had their own mobile phones.

Torrey, who is principal of Somerfield School in Christchurch, said the trend towards younger children being digitally connected had taken off in Canterbury since the earthquakes.

From an educationalist point of view, mobile phones, iPads and other devices were used in conjunction with learning.

Telecommunications Users Association chief executive Craig Young said there had been a general reduction in mobile companies' lower-end plans during the past few years.

Spark-owned Skinny mobile brand has a new $9 a month prepay offer, catering to first time smartphone users with text, calling and data.

Skinny general manager Ross Parker said young people considered having a smartphone a necessity and are always after the latest gadgets.

Spark offered a $19 value prepay pack but was launching a specific pupil offer next month.

Vodafone's cheapest prepay offer was $9 a month and included text and calling.

2degrees' most popular back-to-school offer was an $89 smartphone, paired with a $19 prepay plan.

Torrey said digital devices were needed to support learning but it was essential parents, teachers and pupils continued to educate themselves on the risks.

Today marks international Safer Internet Day. The initiative, started by the European Union, was in its 11th year and would largely focus on young people this year.