amigo614,

Thanks for asking this very important question. We know that a lot of people rely on WiFi as a source of their internet bandwidth. There are some things that have happened in the last couple years that have caused some customers to notice data usage in areas where WiFi is also present. Most high-end phone manufacturers have recently built in options that allow for simultaneous WiFi & cellular data use. They also can allow the phone to pick which network to use dependent upon on the quality & speed of the available connections and what action you're trying to do. Some of these features are Apple's" WiFi Assist", Samsung's "Smart Network Switch", and LG's "Avoid Bad WiFi Connections".

Features like this can all be turned off in your settings to limit your unwanted data use. They can greatly enhance your phone's performance, but you certainly need to be aware of these as well as any WiFi sleep settings on your router & phone to prevent unwanted data use. As others here have said, to be absolutely certain you can just turn mobile data off.

EricW_VZW
Follow us on TWITTER @VZWSupport
If my response answered your question please click the _Correct Answer_ button under my response. This ensures others can benefit from our conversation. Thanks in advance for your help with this!!