Block Spam Calls with

Picture shows a spam can with a red circle and bar superimposed on it.

Block Spam Calls with

Are you frustrated by the complete ineffectiveness of the government’s National Do Not Call Registry?

When this registry went live in 2004, we signed up immediately. Nuisance calls dropped off remarkably. However, Congress never voted to allocate any actual money for enforcement – one suspects that certain powerful groups within Congress are personal owners of the spam-call generating businesses. In recent years, the spam-call industry has recognized that the Do Not Call Registry is a national joke and begun ignoring it with abandon.

Facing a Congress that actually seems to like spam-call generating industries, the Federal Trade Commission eventually realized that they were never going to get anywhere in terms of actual enforcement. As such, they decided to make lemonade out of the lemons. In 2013, they scraped together $50,000 and announced a contest for the best free-market solution to the problem. The winners were announced on 2 April 2013. is the direct descendant of one of the two winners of the FTC prize.

How Does it Work?

The key hook that NoMoRobo uses to intercept the spam calls is a very simple feature that is offered by most land-line and VoIP providers in the United States: the option to ring a second phone number when an incoming call arrives. Say your carrier is Vonage and your phone number is: (512) 543-1234. One of the options in your Vonage account is the ability to designate another number that rings at the same time your number rings. Say you set up your account so that this second number is: (415) 987-6543. When anyone calls your number (That is: (512) 543-1234) then both your number and the other number (that is: (415) 987-6543) ring at the same time. Furthermore, both numbers receive the same caller ID information.

Picture shows a robot delivering a can of SPAM to the telephone number which in turn rings NoMoRobo as well as the home phone

How Works

That is really all it takes. You sign up with NoMoRobo. Once you are registered, you logon to your carrier’s account and setup NoMoRobo’s phone number as your second phone number. The setup is really simple and only takes a minute or two.

Once you are setup, as calls come into your phone number, they also arrive at NoMoRobo simultaneously. However, since NoMoRobo serves a very large number of customers, they can see things that you can’t. For example:

  • They can see a single source number sequentially dialing its way through an area code.
  • They can see a single source number placing hundreds of calls per minute.
  • They can see a source number that other NoMoRobo callers have flagged as a spam robot.

If NoMoRobo thinks the call is spam, it simply answers its line, holds for a half second or so and hangs up again. That terminates the call. At home, you hear a single ring.

The single ring turns out to be much less intrusive than the persistent ringing of a spam call without NoMoRobo. In fact, I kind of like the single ring. It is sort of like sitting outside on a warm summer night, drinking a beer, and listening to the bug zapper fry insects. Each zapping sound yields a sort of visceral pleasure. Likewise, I now have found that I enjoy the sound of the single ring: “Another irritating spam call hammered by NoMoRobo!” Time to crack open a beer.

What About False Positives/Negatives?

Picture shows NoMoRobo's user interface for reporting a number (step 1)

Report a Number Step 1

Since you are still getting the single ring, you are also getting the caller ID string. If you have a reasonably modern home telephone, the calls blocked by will show up as a series of “missed calls”. You can review these periodically to see if anything is getting blocked that should not be.

Picture shows NoMoRobo's user interface to report a number (step 2)

Report a Number Step 2

In either case, whether it was a call that should not have been blocked or a call that should not have gotten through, it is very easy to report a problem. You simply log on, fill in the details, and press submit.

We have been using the service for several months now and it is remarkably good. I haven’t detected anything that was erroneously blocked and we have had exactly one call that should not have gotten through – some annoying, local Texas political harangue. It took less than a minute to report the bad number.

How Much does it Cost?

For home phones, the service is free. NoMoRobo’s business model is to serve consumers free in order to collect the data about the bad actors. NoMoRobo will then charge businesses for the service, use the data provided by the large base of consumers being served for free.