Open Settings
Tap Phone
Tap Blocked Contacts
View the list of blocked numbers and contacts
To check blocked contacts in Messages, open Settings
Tap Messages
Tap Blocked Contacts
To check blocked contacts in FaceTime, open Settings
Tap FaceTime
Tap Blocked Contacts
To check blocked contacts in Mail, open Settings
Tap Mail
Tap Blocked Contacts
To unblock a contact, tap Edit or swipe left on the contact
Tap Unblock or Delete