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October 30, 2017

Three Questions and Answers About the Mobile Phone Blacklists

Over the last few months the apparent acceleration in adoption of blacklist services and applications has caught the attention of contact center leaders. The concern over blacklists is understandable since a blacklisted number could make it more complicated to reach a customer. This, in combination with the fluid regulatory environment spanning the TCPA, CFPB, and FTC, is compounding the challenge of cell phone outreach.

So, what do contact center leaders need to understand about blacklists? Are they having an actual impact? How do you manage your operations with them in the mix? As the saying goes – Knowledge is Power – so here are some key points about blacklists you should know, as well as tips on how to work with them in your contact centers.

First question to ask, “What are the various types of blacklists?”

We’re going to quickly look at three types of blocking methods and blacklists:

  • The FTC ‘Do Not Call’ Data List 
  • Mobile blocking services
  • Mobile phone blocking apps

1) The FTC ‘Do Not Call’ Data List 

The Federal Trade Commission posts files on a daily basis (M-F) containing the phone numbers reported by consumers that have made an unwanted/SPAM call. The focus of the FTC Do Not Call (DNC) Reported Calls Data List is to provide carriers and developers with up-to-date data about phone numbers that have been reported by consumers as undesirable. This ‘blacklist’ data contains information including the phone number, time and date of the call, location of the consumer and the subject matter. The FTC reported call lists data can be found here: The FTC Blacklist Data

2) Mobile phone blocking services:


Blacklist Service Screenshot

The next level of blacklisting type is a carrier or third party provided service facilitating call blocking. These services can combine with an on-device application to leverage crowd-sourcing capabilities that generate “blacklists” shared with/by other users. They can provide notices on the incoming call screen with the caller’s information and the ability for the consumer to designate how to disposition the call.

Service carriers compile blacklists for these services through a number of sources including:

•  FTC managed blacklist data

•  Local phone contact list comparison

•  Basic CNAM database comparison

The mobile carriers may offer these blocking capabilities at no cost or for a monthly fee.

3) Mobile phone blocking apps:

On device phone number blocking apps have been around for a while. These apps may not be nearly as impactful as the blocking services, but they still provide cell phone users with additional options to choose from. These applications use various methods to limit or block the calls the consumer receives. Some simply send any inbound call that is not tied to a specific contact in the consumer’s address book straight to voicemail. Others allow the user to designate specific numbers in their address books that should receive the ‘direct to voicemail’ treatment when such calls come in.  

The next, and perhaps more important, question to ask is: “How is this impacting contact center performance?”

To determine the potential impact of “blacklisting,” LiveVox analyzed our real-time contact center connection data across our clients. Knowing that Blacklist apps and services mainly send calls directly to voicemail, one would anticipate a notable decrease in connect rates.

After extensive analysis comparing data over the past 18+ months, our data shows little, to no, reduction of connect rates across all of our clients, meaning the impact of the FTC list and blocking apps for our clients remains minimal. Other businesses not on LiveVox many have lower connect rates and be impacted by blacklists to a greater degree.


LiveVox Connection Rates By Month

Although there is minimal impact to performance, having a number show as “likely spam” on a consumer’s phone is still not the greatest from a public relations perspective.  We have recommended to our clients that, should this happen, they have a standard talk off piece for agents to explain this description on the consumer’s phone.

As the concern over blacklists is still a relatively new factor, we will continue to closely monitor contact and connect rates for our clients, while watching for any broader trend changes for this critical metric.

Final question: “What does the future hold?”

In the near term, contact centers should monitor the FTC managed blacklist data for their own numbers and adjust accordingly. This includes having a strategy for managing affected numbers within specific call center operations. LiveVox actively monitors and analyzes the FTC managed blacklist for our clients to minimize the potential impacts of these listings. In addition to supporting caller-ID rotation, LiveVox performs proactive reviews and management of our clients’ local caller-ID packages. We also rotate and manage our clients’ 1-800 #s should they be flagged. 

Over the longer term, as service carriers continue to integrate blocker apps into their overall “blacklist” services, LiveVox believes the individual blocker apps will decline in usage and service carriers will have a centralized location of flagged numbers. Additionally, the industry as a whole continues to make strides towards the management and impact of blacklists through strategic initiatives such as potential “whitelists” and the “SHAKEN and STIR” initiative for call authentication. A “whitelist” would comprise of industry numbers that have a legitimate business purpose. SHAKEN and STIR are initiatives to set industry policies for service providers in regard to call authentication and certificate standardization.

As this situation evolves, LiveVox will continue to keep clients informed of its progression. Should you have any questions or concerns regarding the blacklists and strategies to manage their impacts, please reach out to us and our Business Consultants will set up an appointment to discuss these items with you.

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About LiveVox

LiveVox (Nasdaq: LVOX) is a next-generation contact center platform that powers more than 14 billion interactions a year. By seamlessly integrating omnichannel communications, CRM, AI, and WFO capabilities, the Company’s technology delivers an exceptional agent and customer experience while reducing compliance risk. With 20 years of cloud experience and expertise, LiveVox’s CCaaS 2.0 platform is at the forefront of cloud contact center innovation. The Company has more than 500 global employees and is headquartered in San Francisco, with offices in Atlanta; Columbus; Denver; New York City; St. Louis; Medellin, Colombia; and Bangalore, India. To stay up to date with everything LiveVox, follow us at @LiveVox or visit

To stay up to date with everything LiveVox, follow us at @LiveVox, visit or call one of our specialists at (844) 207-6663.

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