RoboExtension

My solution is very simple! Each person or each phone number would have a personal extension that can be modified whenever the owner chooses to have the extension changed. So whenever you give someone your phone number you will also have to give them your extension as well. The Robo calls will not go through unless they have your extension. If they figure out the extension, the person the phone number belongs can decide to change the extension. Everyone who makes a call will also have to enter the extension of the person they're trying to reach, even if the phone number belongs to a single person. The provisions of the modifiable extensions can be made, for free, by the carrier or the phone company the customers are using. The carrier will not have to use an extension to call the customer directly. Once the extension is set up, the customers will have to inform everyone who has that number or any documentary with that number to include the new extension. The phone company can also make it possible for customers to have separate extensions based on calls the customers may expect from family members, personal, or business phone calls from contacts they already have. The extensions can be from 1 to 4 digits, maybe 5.

Another possibility is to have incoming phone numbers that are not in the contact list go directly to voicemail and the customer can decide whether or not to add the new phone number to the contact list or just delete the voicemail.