Over the last few months, the apparent acceleration in the adoption of cell phone 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 cell phone 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.

Latest cell phone blacklist updates for 2023/2024

As of 2023, there are fewer unwanted and robocalls traveling across carrier networks, but many consumers are still receiving spam calls from unknown numbers despite STIR/SHAKEN being the law of the land for a year now. The number of robocalls this year is expected to reach 48.5 billion, down only slightly from 50.4 billion in 2021, according to the latest figures by YouMail, a robocall blocking and tracking firm.

Since the implementation of STIR/SHAKEN, the FCC is expanding its partnership with individual states in order to fight robocalls, and this too could make an impact on robocalls. States like Florida have enacted their own min-TCPA. Carriers are now providing anti-robocall tools allowing consumers to blacklist unwanted or unknown numbers. And many telecommunications providers are also adding to their robocall protection arsenal with support from third-party call blocking apps.

Blacklisted phone meaning

Blacklisting or blacklisted phones mean phone numbers that have been compiled into a list of contacts that you want to be disconnected from immediately.

Phone blacklist check

IMEI numbers, or International mobile Identity numbers, that were reported by the owners and operators as lost or stolen can be identified through a blacklist check. There are blacklist databases that contain IMEI numbers of phones that were bought in a contract and the owner stopped paying the provider on that number. Most operators share their databases so, if your phone is blacklisted, it is very possible that you will not be able to use your phone with any local operator or even all operators.

To check whether a mobile device has been blacklisted you can find many free services online.

What are the various types of blacklists?

Blacklisting can happen to a phone—meaning the device itself-—or a phone number.

When a device is blacklisted, it’s either because the phone has been reported lost or stolen or its account has an unpaid balance. This works via a numeric identifier most phones have called an international mobile equipment identity number, or IMEI. If the phone doesn’t have an IMEI, it most likely has an alternative number called an electronic serial number, or ESN.

When the phone is turned on and connects to a network, the IMEI is transmitted to the carrier, which then does a cell phone blacklist check. If the phone is blacklisted, it won’t be able to connect to the network at all. If the IMEI checks come back clear, calls can be made and received as normal. You can find out if your phone has been blacklisted by running your number through a blacklist checker or by calling the carrier.

When a phone number is blacklisted, it’s because that number is known for making unwanted or spam calls. Calls from that number will be blocked or sent directly to voicemail, either by the recipient’s phone carrier or a third-party app.

Both of these blacklisting situations can cause problems for companies that are trying to reach customers. 

Now, 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

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.

Mobile phone blocking services

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.

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.

How is blacklist compliance impacting contact center performance?

To determine the potential impact of “blacklisting,” we 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 connection rates across all of our clients, meaning the impact of the FTC list and blocking apps for our clients remains minimal. Other businesses may have lower connect rates and be impacted by blacklists to a greater degree.

Although there is minimal impact to performance, having a number shown 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.

What does the future hold for Cell Phone Blacklists?

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. We 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, we 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, we 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 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, we 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.