I was getting two to five calls per day from fake IRS agents, web development companies based in India, cruise offers, and hotel deals.
Nearly all spam calls were coming to two numbers. Both of these numbers were VoIP (Voice over Internet Protocol) numbers. Both of these numbers are hosted on the VoIP.ms service. I think I’m paying $0.85 per month for each number. And then maybe $0.01 per minute talk time. The cost is minimal. Amazingly, included with these minimal rates is the ability to set up a voice menu system.
I suspected many of the spam calls are automated and sometimes gang-dialed. (Gang dialing is calling more than one number at the same time and going with the phone that answers the call first.) Consequently, there would be no one on the line to hear which button needed to be pressed to actually route the call to a phone and make it ring. Working on that assumption, I set up a simple voice menu system.
The initial announcement that a real person would hear goes something like this:
Thanks for calling 206-xxx-xxxx. Press one to ring a phone that a human can hear and answer. Press two to leave a message.
Once I had this menu system in place my spams calls — so far — have gone to ZERO!
On a side note, I used VoIP.ms to help a lawyer get phone service in two locations. He has two residences: one in Seattle and one on the coast at Pacific Beach, Washington. He has two phone numbers. With the VoIP.ms service I set up a system that would ring the phones at each location simultaneously. Voice mail is sent by email and is accessible by phone and not dependent on any of the two locations.
UPDATE February 22, 2018: Since I implemented my anti-spam calling menu system, not one spam call!
If you would like some help implementing something like this, get in touch. My fees are reasonable.