From a Home screen, swipe up or down from the center of the display to access the apps screen.
These instructions only apply to Standard mode and the default Home screen layout.
Tap Phone .
Tap the Menu icon (upper-right).
Tap Block numbers.
Enter the 10-digit number then tap the Plus icon (+) located on the right or tap Contacts then select the desired contact.
To block or unblock unknown calls, tap the Block unknown callers switch to turn on or off .