Check whether your landline service offers call blocking or call screening
Contact your phone provider and ask them to block the specific number
Use your phone’s built-in call block feature if your landline handset supports it
Add the number to a call rejection or blacklist list on a compatible cordless phone
Enable anonymous call rejection if the unwanted calls are blocked caller ID calls
Use a call-blocking device between your phone line and handset
Register your number on the National Do Not Call Registry if the calls are telemarketing calls
Report repeated harassing calls to your phone provider and local authorities if needed