1. From the Start screen, tap the Messaging tile.
   
2. Touch and hold the desired conversation.
   
3. Tap block number....
   
4. Tap accept.
   
5. Tap ok.
   
6. The phone number will be blocked. To edit blocked numbers and ensure that blocking is toggled on, tap the Menu icon.
   
7. Tap blocked messages.
   
8. Tap blocked numbers.
   Note: Ensure that the Block calls switch is toggled on.
   
9. Blocked numbers will be displayed. To edit, touch and hold the desired blocked number.
   
10. Tap unblock.