Open the Phone app
Tap the recent call or open the keypad
Tap the number you want to block
Tap More options or the three dots
Select Block number or Block/report spam
Confirm the block
Open the Phone app
Tap the three dots or Settings
Tap Blocked numbers
Tap Add a number
Enter the phone number
Tap Block
Open the Contacts app
Open the contact you want to block
Tap More options
Tap Block number
Confirm the block