Check whether your landline service provider offers call blocking
Log in to your provider account or contact customer support
Add the unwanted number to your blocked numbers list
Use your phone’s built-in call blocking feature if available
Enable anonymous call rejection to block private or hidden numbers
Install a call-blocking device on your landline
Set up call screening or caller ID filtering through your phone system
Use a call-blocking service from your carrier
Register your number with a do-not-call list if the calls are telemarketing
Contact your provider to report repeated harassing calls