ONE in three Australian parents have been hit by unexpected smartphone bills due to their children's phone use, a survey by Optus shows.
The survey of more than 1200 parents of children aged eight to 21 found 33% of parents had received a bill of $300 or more for their children's phones.
Optus chief executive Kevin Russell said the rising use of smartphones to stream video and music was leading to what he called "bill shock".
"Without simple precautions, younger smartphone users, often unfamiliar with how much data their new 4G mobile is using, are more likely to exceed their limits, leaving mums and dads footing the bill," he said.
The survey also revealed 66% of parents surveyed were faced with paying for their children's phone use above the post-paid limits.
It also showed 75% of parents were concerned about their children's mobile use with 65% not trusting their children to stay within data download limits.