From the Settings app, tap Connections.
Tap Data usage.
Tap Billing cycle and data warning.
You can also turn off mobile data when you're in areas where you don't want to use any data.
Tap or slide the Set data warning switch 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 Data warning.
Enter your prefered data usage warning.
Tap Set.
Tap or slide the Limit mobile data usage to ON.
Tap Data limit.
Enter your preferred data usage limit.
Tap Set.
Tap Start billing cycle on.
Select a new usage cycle reset date.
Tap Set.
You've completed the steps!
