My LG G3: I need to figure out how to stop my phone from roaming to other networks while I am away?

[AC Question]

My LG G3: I need to figure out how to stop my phone from roaming to other networks while I am away

I turned data off on my phone. It is always off. Will it be able to roam to other networks while I am not near my home network, say for incoming calls? My phone doesn't have a roaming on/off button that I can see.
Thank you in advance

 

[Klotar]

To toggle Roaming, go to Settings (gear icon), Mobile Data, Overflow Menu (3 dots), then Mobile Networks. Uncheck Data Roaming.

Not sure if all G3 variants get there the same way but hopefully similar.

As for calls, you "sort of" always roam but will not get charged unless you make or answer a call, retrieve voicemail or send text messages. By "sort of", I mean that the G3 will use other networks when the home network is unavailable for emergency calls (e.g. 9-1-1) only. I believe that most modern smartphones now do this.