Open the Phone app
Go to Recent calls or Call history
Select the mobile number
Tap Block, Block number, or More options
Confirm the block
Open the Contacts app
Select the contact
Tap More options
Choose Block contact
Confirm the block
Open Messages
Open the conversation from the number
Tap More options
Select Block number or Block contact
Confirm the block
Open Phone settings
Tap Blocked numbers or Call blocking
Add the mobile number
Save the changes
Use your carrier’s call-blocking service
Log in to your carrier account
Add the number to the blocked list
Save the changes
Use a third-party call-blocking app
Install the app
Grant required permissions
Add the mobile number to the block list