Open the Phone app
Tap Recents, Contacts, or Voicemail
Tap the info icon next to the number
Scroll down
Tap Block this Caller
Tap Block Contact to confirm
To block from Messages, open the conversation
Tap the contact name or number at the top
Tap Info
Tap Block this Caller
Tap Block Contact to confirm
To block from FaceTime, open the call list
Tap the info icon next to the number
Tap Block this Caller
Tap Block Contact to confirm
To block from Settings, open Settings
Tap Phone, Messages, or FaceTime
Tap Blocked Contacts
Tap Add New
Select the contact to block