1. From the home screen, tap the Apps icon.
   
2. Swipe to, then tap Usage Manager.
   
3. Tap DATA USAGE.
   
4. To change which billing cycle you are viewing usage for, tap the Data usage cycle drop-down menu and then select the desired bill cycle.
   
5. To change your billing cycle, tap Change cycle.
   
6. Tap the Up and Down arrows to reach the desired date, and then tap Set.
   
7. To turn on data usage limits, tap Set mobile data limit.
   
8. Tap OK.
   
9. Drag the limit and/or warning lines up or down as desired.
   Note: When the mobile data limit is active and has been reached, the mobile data block will remain in effect until mobile data is manually re-enabled on the device, the limit threshold is changed to a higher value, or a new data usage cycle begins. If you set data usage limits on your device, they do not communicate with AT&T systems. You will still receive AT&T system generated notifications as you approach your data plan limits.
   
10. To restrict application usage, scroll down and tap the desired application.
    
11. Scroll to, then tap Restrict background data checkbox to enable or disable.