The financial risks of children using free apps and social media on mobile devices have been flagged by the UK regulator of premium rate telephone services.

The Children as Connected Consumers report by PhonepayPlus warns that parents who do not discuss which apps children use could be hit by monthly bills of hundreds or even thousands of pounds. The regulator saw a 300 percent increase in complaints about children and apps in the past year.

Two-thirds of 16 year olds have downloaded free apps on their devices, with in-app billing and some cases of malware presenting risks.

Malware can charge users’ phones without their knowledge, with cases of children being charged £15 by fake versions of Android games such as Angry Birds, Assassin’s Creed and Cut the Rope, every time they open the app.

Tips to avoid these problems including registering the phone as a child’s phone with mobile operators; discussing controls available with operators and contacting them with any issues; educating children about what information they enter using their phone; keeping track of the apps children are downloading; and referring to the www.phonebrain.org.uk website for information on safe and secure phone use.