Enable your phone’s built-in call blocking or silence unknown callers feature
Block private or unknown numbers in your phone settings
Contact your carrier and ask for anonymous call blocking
Use a call-blocking app from your app store
Register your number on the National Do Not Call Registry
Do not answer calls from No Caller ID numbers
Let unknown calls go to voicemail
Report repeated harassment to your carrier
Contact local authorities if the calls are threatening or abusive
Ask your carrier about changing your number if the calls continue