Children making unauthorised in-app purchases on their parents' phones may account for £30.9 million of mobile revenue a month, Microsoft has claimed.

The startling statistic is the result of a survey of more than 2,000 parents across the UK, with the Redmond giant claiming that over a quarter – 28 percent – stated their kids had made rogue purchases on their handsets.

The reason? Microsoft claims that 17 percent of UK parents share their smartphone and tablet passwords with their children, with 23.5 percent opting not to have a password at all.

Microsoft's angles

"Our research reveals parents are worried about the impact of app and in-app purchases on their bills and we understand the stress this can cause," said Microsoft's head of marketing for Windows Phone UK Brett Siddons.

"With technology becoming more and more intuitive, it’s important that parents can trust in the technology they use and feel as safe as possible when handing over their smartphone and tablet devices to their children."

Microsoft's numbers are, of course, designed to promote the validity of Windows Phone's Kids Corner, which allows parents to put certain apps and games in a dedicated, locked off hub.



It's a tool that - along with other security measures - means the smartphone can be shared around the family without the parent worrying that their children are deleting vital emails, or purchasing apps from the Windows Store without permission.

Next steps

Nonetheless, Microsoft's survey taps into a growing feeling that the industry needs to take greater responsibility for the deployment of in-app purchases, with more and more children having access to smartphones and tablets.

Apple was recently moved to settle with a group of parents in the US that had taken legal action against the company after their kids amassed huge monthly bills.

The firm has also launched an in-app purchase guide on the iPad version of its App Store.

In the UK, meanwhile, the Office of Fair Trading has announced it is to investigate the increasing number of free-to-play apps it believes are aimed at children, and the way in-app purchases are pushed within them.

As such, Microsoft's claims that kids who make unauthorised purchases add an average of £34.18 to their parents' monthly bill - totaling £410 per year – is likely to garner interest.

The firm concludes that 8 year olds are the biggest spenders, amassing bills of little short of £60, although Microsoft notes that 36 percent of children aged 4 and under have also made purchases without permission.