Robocalls from a Toll-Free Number? That should never happen, right?


That’s my smartphone buzzing in my pocket. I was expecting a call from my warranty company. I took out the phone and looked down at the screen. No name, so the number was not in my contacts. Could it have been the warranty company calling back? Or another robocall?

Let me explain – two days prior, while walking back from a socially distanced lunch, I had a near collision with a messenger cyclist, dropped my phone and had it run over by a vehicle. The phone was crushed and no longer functional so I pulled out the SIM card to use in a backup phone while I waited for a replacement. I had placed many calls to the warranty company to report the incident. A claim was filed and was waiting for my dear replacement and the chance to put my digital life back together. 

RobocallingRobocalls have been around ever since computer-telephony integration started back in the early 1990s. Computer-telephony integration ensured that, in addition to humans dialing digits to initiate calls, computer programs also could. This technology allowed them to initiate many at the same time, being limited only by the number of telephone lines connected to them. They also grew in sophistication and were able to recognize tones from fax machines, modems and answering machines and responding appropriately. The initial impetus for this was really automation and efficiency by allowing contact center staff to place and receive calls, thus saving time and increasing productivity.

Unfortunately, along with these technological advances, came the opportunity to exploit them. Here are three things that have, for better or worse, helped to set the stage for robocalling:

First, the advent of the Internet, as well as Voice-over-IP (VoIP) based calling, presented many new developments. The cost of computer-telephony equipment plummeted and with it, the cost of long-distance telephony came down as well. Long-distance tariffs in the US used to be in the 10-20 cents per minute range in the early 1990s, providing deterrence to nuisance calls. Today it is well below one cent per minute, and most consumers have plan bundles that they are not even made aware of these tariffs in their monthly communications bill. In fact, with the increased use of mobile telephony, the notion of “long-distance” in and of itself has become antiquated. Additionally, the US has the lowest inbound international call termination charges which allow robocall operators to proliferate abroad and specifically target Americans.

Second, voice became digital – implying that the entire mechanics of the call process – originating calls, communicating, hanging up – could be totally automated. In response, DIY kits and software became more readily available, thus letting more parties take advantage of automated solutions. A lot of legitimate use cases were similarly borne out of this – such as automated notifications for school closings, game updates, emergency alerts, etc.

Third, and most importantly, digital telephony enabled Caller ID modification(s). To explain: Caller ID represents the originating phone number. In early fixed-line telephony, it represented the calling party’s phone number (as it still does today). Conversely, in mobile telephony, it represents the caller’s phone number, as it is stored on the phone’s SIM card. For better or worse, however, VoIP and new technologies allow Caller ID information to be manipulated and changed while placing calls.

This became a masterstroke that bad actors all over the world immediately took advantage of. For example, a bad actor operating and calling from Romania to the US could spoof the originating phone number to make it appear as a US-based 10-digit number, thus increasing the probability that the call would be answered. This quickly became a greater global problem that was not exclusive to fraud against Americans. Specifically, with this technology, robocallers anywhere could target any recipient in any country for their oft nefarious purposes. 

Unsurprisingly, Caller ID spoofing was able to exponentially increase the number of robocalls placed globally.

Since its inception, robocalling and its bad actors have figured out new tricks. This includes incorporating Toll-Free Numbers into Caller ID spoofing technology. Toll-Free Numbers, whose original purpose was to allow for a party being called (versus the calling party) to be charged for a call, have expanded their range, use and scope. Somos, as a trusted administrator of the Toll-Free Numbers for North America, has broadened the number range due to demand.

Today, Toll-Free Numbers (TFN) include seven area codes: 800, 888, 877, 866, 855, 844 and 833 and businesses all over North America view a TFN as a trusted way to engage in communications with their customers, partners and employees. Otherwise stated, TFNs are an important statement of a company’s brand and business identity. In fact, the role of the Toll-Free Number as a mainstay of trusted communications has increased in demand over the years so much that as of today, over 41M TFNs are currently active.

Scammers use various techniques to spoof Toll-Free Numbers. This includes taking active numbers and changing a few digits; taking the calling party’s number and changing the area code to a Toll-Free area code; or outright pilfering active numbers, thus causing reputational harm to the legitimate business that owns the number. The Federal Communications Commission (FCC) imposes stiff penalties on these types of infractions.

As the authoritative administrator of the SMS/800 TFN Registry®, it is easy for Somos to know which TFNs are active, which are inactive and which have not yet been provisioned. To be proactive in the fight against fraud, Somos has identified inactive Toll-Free Numbers in the RealNumber™ database as Do Not Originate (DNO). It is important to flag these numbers as DNO because TFNs that are inactive should never be used for outbound calls. Toll-Free Number service providers (also known as Responsible Organizations or Resp Orgs for short) are able and empowered to access RealNumber and identify active numbers that they manage as DNO, for those TFNs that will never originate traffic (inbound only). This helps protect the Resp Org’s enterprise customer’s trusted business number(s) from fraudulent call activity and illegal spoofing.


The phone buzzes again. Seeing a recognizable Toll-Free Number on my Caller ID gave me a higher level of confidence that the incoming call might just be the warranty company. I answered the call, eager to hear about the status of my replacement phone.

“Hello,” I said expectantly. 

“Hi Sri, this is the warranty department calling about your phone.”

AND we’re back in business!!

Sri Ramachandran
Sri Ramachandran
SVP & Chief Technology Officer

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