Robocallers, scam callers, and other general spam calls continue to be a big problem in today's ever increasing mobile environment.
In its ongoing endeavors to enhance security, Apple has introduced a feature to iOS 13 that they're dubbing "Silence Unknown Callers." This setting is intended to protect the user against spam callers and calls from people you don’t know. It’s a simple toggle on or off.
Under the Settings tab, tap Phone.
Toggle to enable the Silence Unknown Callers control.
When the setting is enabled, the new iOS, which launches to the general public today, uses Siri intelligence to allow calls from numbers found in your Contacts, Mail, and Messages apps. All other calls automatically go to voicemail. Not only does this feature support the FCC’s new STIR (Secure Telephony Identity Revisited) and SHAKEN (Secure Handling of Asserted information using tokens) standards, it also displays a check mark next to calls in the Recents list when those phone numbers are carrier verified. Verified numbers mean the call is not spoofed.
Unfortunately, this isn't quite a perfect system, as you need to take care not to miss important calls from people not listed in your contacts. Always check your voicemail for calls to ensure you don’t miss a needed communication.
In addition to this feature, there are a couple of fantastic apps that help reduce the number of spam calls you may receive on a daily basis. My top two recommendations are AT&T Call Protect (If you are on an AT&T) plan, and Hiya. Both of which use the same technology in conjunction with one another to block calls that have already garnered numerous reports against them, and warn you that a call may be "potential spoofing" , so that you can make a more informed decision as to whether or not to answer the call.