I received a rather unpleasant shock this morning. In 8 days since owning the iPhone 6S Plus I have used 2.5gb of mobile data. So I checked my wife’s 6S and her phone had used 750mb of data.

Now in my case I am fortunate that I have an unlimited plan, but I use 2-3gb of data maximum per month, not per week. In the case of my wife, she has a 500mb data plan since she never uses anymore than 100mb per month.

So what caused this huge swing in mobile data usage. It turns out there is a setting which is on by default called WiFi Assist. It is located in the main settings app, mobile data and then scroll all the way down to the bottom of the list, an untick the Wi-Fi assist toggle.

Hopefully you haven’t got stung for high data charges by now.

Update – Michael left an extra bit of advice is the comments. Thanks for that. “As well as turning off wifi-assist. Make sure that you go into iCloud settings and iCloud Drive, scroll down to the bottom and turn off “use mobile data” it’s something I read about on Twitter that really makes a difference, that some sites have missed to mention that seems to do the trick, (You really want to be backing up all those 12 mb pictures and video files only on wifi! )”