Last Updated: Jun 20, 2014
You may have issues with calls if you have:
These steps help identify and resolve the underlying cause. After completing each step, test to see if the issue is fixed. If not, continue to the next step.
Verify airplane mode is turned off.
Airplane mode is a feature that prevents your device from sending or receiving a wireless transmission.
Verify your HTC One M8 is connected to the Sprint network using Sprint Zone.
Be sure your HTC One M8 is connected to the Sprint voice network to make or receive calls.
Verify if coverage is available at your current location.
If your HTC One M8 has low signal strength, see if your location is within Sprint voice coverage on the Sprint coverage map.
Reset the network settings.
Resetting the network settings reconnects your phone to the Sprint network and does not erase any of your content or data.
Do you know if other Sprint customers are experiencing the same issue in the same location?
Note: To optimize device performance, be sure your HTC One M8 is running the most recent device software. Check for software updates.
If you're still having issues, please contact Sprint Customer Care for more help.