From the Home screen, drag down the Notification panel.
Tap the Settings icon.
Tap Mobile data.
Switch Limit mobile data usage to ON.
From this screen, you can limit your data usage and set up alerts for when you're reaching your data usage limits for the current month.
Tap OK.
You can also turn off mobile data when you're in areas where you don't want to use any data.
Drag the red bar to set a data usage warning.
Drag the orange bar to set a mobile data limit.
You've completed the steps!
