Open the Phone app
Tap Recents or Dialer
Tap the info icon (i) next to the number you want to block
Tap Block Caller
Confirm by tapping Block Contact
Open the Phone app
Tap Contacts
Select the contact or enter the number
Tap Block this Caller
Confirm
Open Settings
Tap Phone
Tap Blocked Contacts
Tap Add New… (or Add)
Enter the number
Tap Block
Open Settings
Tap Messages
Tap Spam and Blocked
Tap Blocked Contacts
Add the number
Open the Messages app
Open the conversation with the number
Tap the contact name or number at the top
Tap Block this Caller
Confirm
Open the Contacts app
Select the contact
Tap Edit
Find Block Contact (if available)
Turn on or select Block
Save
Install and open your carrier’s call-blocking app (if provided)
Add the number to the block list
Save changes