Data usage even with Data turned off

[Pooky]

My son leaves his data turned off all the time (cause he is a good kid) yet his account still shows data usage, even while he is sleeping and his phone is not in his room.  I have checked that all the apps have data turned off as well as the main data off

[NFtoBC]

What phone is he using?  Some use data to download updates in the background, even if data is turned off.

[xl]

How have you determined data is off?

• airplane mode does not count.  On some phones, this can be bypassed.
• turning on wifi does not count... sometimes the phone goes into an area of poor wifi coverage and reverts to cellular data.

[Lola]

My son has had this issue using an iPhone 5s.

A little help here: http://lifehacker.com/5957947/how-to-figure-out-which-apps-are-using-your-smartphones-cellular-data-...

I've never had the issue. I use Norton on my phones. Norton's App Advisor tells me when an app will use high background data, then I don't install it. Norton also scans my installed apps for changes in app behavior, and then warns me so I can uninstall problem apps. Norton has saved me loads of trouble. 🙂