Open the Phone app
Tap Recents, Contacts, or Favorites
Tap the info icon next to the number or contact
Scroll down
Tap Block this Caller
Tap Block Contact to confirm
Open the Messages app to block a text sender
Open the conversation
Tap the contact name or number at the top
Tap Info
Tap Block this Caller
Tap Block Contact to confirm
Open the FaceTime app to block a caller
Tap the info icon next to the contact
Tap Block this Caller
Tap Block Contact to confirm
Go to Settings
Tap Apps
Tap Phone, Messages, FaceTime, or Mail
Tap Blocked Contacts
Tap Add New
Select the contact to block
To unblock, go to Blocked Contacts
Swipe left on the contact
Tap Unblock