Robocall Prevention Services: What’s Good and What’s Not


Are you noticing an increase in incomplete caller connections?  Have you seen an unusual uptick in network/system information tones from carriers for previously verified consumer phone numbers?  You may be experiencing the symptoms of new types of carrier, crowd-sourced, or mobile–phone–based call blocking services that often misclassify and even block your legitimate business calls.

There is an increasing number of technological developments, industry and consumer-driven initiatives, and regulatory actions that are intended to protect consumers from scam calls and other types of call abuse.  Many of these actions are a welcome step, both for companies that are diligent in adhering to the rules and best practices surrounding outbound calling protocols, as well as for consumers. With illegal robocalling still on the rise, finding workable solutions to help stem the tide of illegal calls while still protecting the rights of legitimate businesses to communicate with consumers has become much more challenging and complicated.  Unfortunately, some of the call blocking tools that carriers and other providers have developed, some of which are supported by the FCC, often do block legitimate calls.



One of the positive steps that currently is being taken by regulators to curb scamming and robocall abuse is the TRACED Act (Senate Bill S.3655 and House Bill HR. 1602), which has strong bipartisan support in both the U.S. House of Representatives and Senate. The proposed bill targets robocall scammers with fines up to $10,000 per call, while also extending the statute of limitations for criminal prosecution of these offenses from one year to three years. The bill also mandates that voice service providers implement a call authentication framework called STIR/SHAKEN within 18 months. Some carriers are ahead of the game and already are engaged in interop testing of caller authentication solutions. As part of this proposed legislation, the FCC will protect carriers from liability for unintended or inadvertent blocking of calls as a result of using this framework.


As noted above, the STIR/SHAKEN framework is designed to help validate legitimate calls and prevent scam calls from reaching end consumers. Within this framework, the originating service provider “attests” to the validity of calling parties by encrypting information in the SIP header. The terminating service provider will decrypt this attestation, and after processing the information against its own verification service, the provider will either deliver or block the call.  Aspect is committed to helping outbound contact centers connect with end consumers and will continue to help organizations navigate this framework.


Call Blocking Services

The methods and regulatory initiatives described above for weeding-out and punishing scam callers who use fake numbers to, among other things, bypass protections from caller I.D. applications are a step in the right direction for protecting both consumers and legitimate businesses. However, a related but separate initiative by well-intentioned telecommunication carriers and crowd–sourced third parties have had both positive and negative impacts. These developments include call technology that utilizes analytics to block calls that conform to various callings patterns and characteristics set by carriers. The problem is, these applications can not only block unlawful or nuisance calls, but also legitimate callers that have been improperly flagged. The fact is, outbound contact centers have been experiencing a growing number of blocked calls by services which often have loosely defined rules for what call patterns or characteristics should trip the call blocking protections. In short, legitimate calls which businesses and consumers would benefit from are often not being connected.

In addition to these call blocking measures applied at the carrier and crowd-sourced level, there also has recently been a proliferation of call blocking applications that are installed on mobile devices. These applications are supplied by carriers or third-parties that block and filter calls based on feedback from subscribers. End users flag inbound calls that they would like to be blocked in the future which, like the call blocking technology applied at the carrier level, helps prevent scams and nuisance calls but also prevent organizations with legitimate interests from reaching consumers. Some of these services reroute calls to prerecorded messages which are intended to waste the time of the caller, which further impairs efficiency for outbound contact centers. The available data indicates that, in addition to these call blocking applications, consumers are submitting telephone numbers to carrier-maintained blacklists to avoid calls from numbers that the end users specify, which only exacerbates the problem for legitimate businesses trying to reach their customers or potential customers.

June 6, 2019 FCC Ruling

The FCC recently issued a declaratory ruling that allows voice carriers to apply, as a default to consumers, the call blocking applications referenced above. That means call blocking services can be activated without the consumer’s knowledge, forcing them to actively opt-out of this service, which they are unlikely to do. These activities already have made an impact on outbound contact centers, especially in the collections business.  As consumers continue to complain to carriers about unlawful or harassing robocalls, in the future, carriers are more likely to block calls, even lawful automatically-dialed calls from legitimate organizations.

In short, the misclassification of legitimate business calls as unlawful, nuisance, or scam calls is a serious issue for many of our customers, and Aspect is committed to helping those of you impacted stay informed and educated.


Aspect is investigating techniques to prevent calls from being flagged as spam in the first place. We are researching third-party services that work with carriers to prevent legitimate calls from being flagged, and ultimately ensure that they are delivered to end consumers. Additionally, Aspect is engaging with our customer’s executives and carriers to raise the visibility of this problem, as well as aligning our mutual interests and exploring solutions.  Finally, Aspect will monitor industry efforts to lobby the FCC to protect legitimate calls while still taking action against scammers.


  • Ensure your outbound lists contain in-service numbers, and that the numbers still belong to the consumer you expect to reach. Callers that originate calls to numbers that are not in-service can cause filtering algorithms to kick-in.
  • If your telecommunications carrier, or the carriers of those you are calling, keep lists of legitimate caller numbers that should be protected from being blocked, ensure that your numbers are included on these so-called “whitelists.” (e.g., T-Mobile offers a portal for reporting improperly blocked numbers. **Please note: even if a number is explicitly whitelisted with the originating carrier, it can still be blocked by the terminating carrier.)
  • Regularly review published robocall complaint data from the Federal Trade Commission  and the Federal Communications Commission  to determine if your numbers are being flagged and/or blocked.
  • Consider all communications channels for outreach campaigns. Studies show (like this  2018 Aspect Consumer Experience Index) more and more consumers are preferring text channels (SMS and other messaging services) when interacting with brands.
  • Become educated and engaged with your legislators and trade associations regarding the FCC rulings and proposed legislation. See links below.


FCC Chairman Pai’s SHAKEN/STIR ROBOCALL SUMMIT… July 11, 2019.

Traced Act. HR1602

Fact Sheet:

FCC: June 6, 2019. Advanced Methods to Target and Eliminate Unlawful Robocalls

Understanding Stir-Shaken


ATIS IPNNI-2018-00018R008

House Memo

ACA International Blog