Open the Phone app
Tap Contacts
Select the contact you want to block
Scroll down and tap Block this Caller
Tap Block Contact to confirm
Open the Messages app
Open the conversation with the contact
Tap the contact name or number at the top
Tap Info
Tap Block this Caller
Tap Block Contact to confirm
Open the FaceTime app
Open the contact or recent call
Tap the info button
Tap Block this Caller
Tap Block Contact to confirm
Open Settings
Tap Phone
Tap Blocked Contacts
Tap Add New
Select the contact to block
Open Settings
Tap Messages
Tap Blocked Contacts
Tap Add New
Select the contact to block
Open Settings
Tap FaceTime
Tap Blocked Contacts
Tap Add New
Select the contact to block
To unblock a contact, open Blocked Contacts and swipe left on the contact
Tap Unblock