In the world of telecommunications, unlisted phone numbers that have gone unused for a specific period may be turned into “honeypot numbers,” or phone numbers assigned by telecom carriers to detect robocalls, spam callers, and scammers.
These honeypot phone numbers are not assigned to actual customers but are actively monitored to identify illegal or malicious calling activities. This tactic helps carriers, governments, and NGOs combat unwanted calls and protect consumers.
This post will explore the concept of honeypot phone numbers, how unlisted numbers become honeypots, why the practice is used, and the specific timeframes different telecom carriers follow before changing an unlisted number into a honeypot.
A “honeypot phone number” is a phone line that looks like a typical number but is used solely by telecom companies to identify and trap malicious actors, particularly robocalls, spammers, and scammers. These numbers are often set up to record calls, track call patterns, identify scammers, and provide evidence to support legal action against violators of telecommunications laws.
These phone numbers are not connected to real people, and they remain inactive in terms of being assigned to end users. Once an unlisted or decommissioned phone number reaches a certain period of inactivity, telecom carriers often turn it into a honeypot number to strengthen their efforts against unwanted and illegal calling activities.
From the vantage point of a professional call center or company that makes outbound calls, these honeypot numbers may seem like they have nefarious intent or are unfairly disadvantageous to their business model. A little bit of insight into why these numbers are used, and looking at some of the results from studies that have been done using them, can help to understand the practice from another perspective.
Between March 2019 and January 2020, a team of academics from North Carolina State University ran a study using 66,606 phone numbers they used as honeypots. Despite being unlisted, these calls received 1,482,201 unsolicited calls within that time frame, many of which came through sudden call volume surges that the team called “storms.”
The team tracked 650 different “storms” of calls during the time frame which followed regular patterns and intervals, helping them to decipher the methods these scammers and spammers were using. The research white paper that the team used to present their findings can be found here, and an article explaining it more succinctly (and in layman’s terms) can be found here.
Another non-governmental group called the Messaging, Malware, and Mobile Anti-Abuse Working Group (M3AAWG) has written an extensive document outlining why it thinks that honeypots should be facilitated and encouraged, with all of their reasons for doing so. That document can be found here.
For legitimate call centers and outbound call makers, it should be understood that these honeypot phone numbers are not designed or meant to entrap you from your normal business operations. These are meant to help prevent or at least subside the current scourge of nefarious phone-based telephone scams that are happening across the nation.
This practice and issue are not specific to the USA, either. This organization is another non-governmental one that is using technology to crowdsource information on UK-based spammers and scammers via honeypot phone numbers as well.
Using good lead & phone number database hygiene and calling practices can help keep you from being ensnared in one of these honeypot operations. If you would like to know more about good lead and phone number database hygiene, our post here outlines those practices in detail.
Telecom carriers hold vast pools of phone numbers, but not all of them are in use at all times. Unused or unclaimed numbers typically fall into two categories:
1. Inactive (Unlisted) Numbers: Numbers that have been disconnected or are not currently in use by any customer.
2. Available Numbers: Numbers that are open for assignment to new customers.
When a phone number is disconnected from a customer, it goes through a period when it remains unlisted or inactive. During this time, telecom carriers must ensure that the number isn't reassigned too quickly to avoid confusion or miscommunication with future customers. However, after a specific period of inactivity, the number may be turned into a honeypot if not reclaimed.
If these phone numbers receive a large volume of calls during this period of being unlisted, the telecom carriers may add it to their database of “dirty” phone numbers and turn it into a honeypot as well. It would not be a good business practice for the provider to assign a phone number to a new customer despite it already receiving a high volume of unsolicited calls before even being listed.
These “dirty” number databases are used by telecom carriers, governmental, and even non-governmental entities to collect intelligence on phone-based scams, spam callers, TPCA violators, and DNC violators.
Different telecom carriers have varying practices when it comes to how long they wait before turning an unlisted phone number into a honeypot. Let’s take a look at the general policies of some major telecom providers.
Verizon typically waits around 45-60 days before making an unlisted or disconnected number available for reassignment. However, if the number isn't claimed, it may transition into a honeypot number. Verizon generally reserves the right to implement a honeypot status on unused numbers after this initial reassignment period.
AT&T follows a similar approach, with a 60-90-day waiting period for disconnected or unlisted numbers. After this period, if the number isn’t reassigned to a customer, AT&T may designate the number as a honeypot, primarily to monitor illegal robocalls and spam.
For T-Mobile, unlisted numbers undergo a 45-day cooling-off period before they are made available for reassignment or turned into honeypot numbers. Once the cooling-off period ends, T-Mobile monitors the number to determine whether it should be repurposed as a honeypot to track malicious activity.
Sprint followed a 30-to-60-day policy for unlisted numbers. With the merger between Sprint and T-Mobile, the policies have largely converged, but the timeline remains within the 45-day cooling-off period.
Smaller carriers or regional telecom companies often have more flexible timelines for when they assign honeypot status to unlisted numbers. Typically, these smaller carriers wait 60 to 120 days before repurposing unlisted numbers for honeypot use. However, this varies based on regional regulations and operational capacity.
Honeypot phone numbers serve a critical role in the ongoing battle against robocalls, scammers, and unwanted spam. By tracking the activity of malicious actors, carriers can analyze the call patterns and behaviors of spammers and phone-based scams. Honeypot numbers provide insight into the methods used by scammers and help telecom providers improve their anti-spam measures.
Additionally, by keeping these honeypots active, telecom companies help protect customers from receiving repeated unwanted calls. Once illegal callers are flagged through honeypot numbers, they can be targeted and blocked more efficiently, benefiting all users on the network.
Take a moment to consider something: how would you feel if you bought a brand new SIM card & immediately began to receive these “storms” of spam or scam phone calls, rendering your phone virtually unusable during the period? This is one reason, as the research above outlines, that discovering how these “storms” operate makes honeypot phone numbers a vital tool for telecom companies.
Honeypot phone numbers are an essential tool for telecom carriers in their fight against robocalls, scams, and spam. By strategically converting unlisted or inactive numbers into honeypots after specific waiting periods, major carriers like Verizon, AT&T, and T-Mobile play a vital role in reducing the number of unwanted calls that reach consumers.
Outside of the carriers themselves, both governmental and non-governmental entities utilize honeypot phone numbers to collect information and intelligence to help combat the problem of spam and scam callers. The studies and PDFs linked above can help shed some light on why these numbers are used and what they are focused on helping to prevent.
Understanding how these honeypots work and the timeframes involved gives you a clearer picture of the importance of responsible phone number management in the telecommunications industry. The next time a number becomes inactive, there’s a chance it’s being used for something much bigger - protecting consumers from unwanted calls and scams.
No, honeypot phone numbers are designed solely for incoming calls and are used by telecom providers to monitor suspicious activity.
If you unintentionally call a honeypot number, you may receive no response or encounter a recorded message. These numbers are not in use by actual customers.
Carriers select unlisted or unused numbers based on their anti-spam strategies and after a cooling-off period, typically ranging from 30 to 90 days.
