1. From the home screen, tap the AT&T folder.
   
2. Tap Usage Manager.
   
3. To set a data limit, tap Limit mobile data usage.
   
4. Tap OK.
   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 limits.
   
5. Drag the handles to set the alert and limit levels.
   
6. Scroll to, then tap the desired app to view data usage details.