How to track Usage

[Hey]

Hello my boyfriend uses my phone and he is trying to convince me that all of the usage activity is not from him and that he's being hacked is there any chance we can help me out

[ksm]

Iam looking for my call logs, so i can see the time date and how long the calls last , for my work. before Saturday. 

[LordAstartes]

Depending on the Phone you use you can go into the APPS Store (I use android) and see through the App how much Data is being used. I as an Android Can also turn off Data Transfer to the Network and Tap into my wifi thus Saving my monthly data limit to whenever I reallllllly neeed it like using apps for shopping etc. 

[Shayan]

 

I just top-up my prepaid phone and to see if that worked, I checked the usage of my app. Surprisingly, I saw 972 mb of my data gone!!! How that is possible? 

[TiniY-2]

Hi, I noticed it says I’ve used 80% or my outgoing calls, leaving me with 20 out of 100 minutes left.

however when I look at the minutes I can only account for about 20/25 minutes of outgoing calls. 
do calls from other apps online count, or how have a used 80 minutes when I only see about 20. 

[AKA]

Usage history is always wildly inaccurate, I can't be the only one...

[EGCF2016]

My husband has had his account for almost a month.  We have 3GB of data but he's showing he has used 2.23GB so far.  He works from home and rarely goes out which is why he has never had his own cell-plan with a major carrier.  I'm shocked that his usage is so high given he's always connected to wifi.  When I look at the detailed usage it shows him using data just twice today (21.95KB and 11.19KB).  I'm guessing this is him scanner his diabetic sensor as he hasn't sent any texts today.  Why is this taking from his data and not wifi?