March 18, 2026
CIDR’s New Report Reveals Trends in Call Flag Behavior
Have you ever wondered why outbound calls suddenly stop reaching customers? Sorry to break it to you, but your caller ID may have been marked as “spam.”
To better understand how this happens, Caller ID Reputation® (CIDR) analyzed phone number reputation activity over four years to see how carriers, call-blocking apps, and data providers label calls. Our 2025 Phone Reputation Statistics Report identified 14.5 million caller ID events last year alone, bringing the total to 45 million since 2021.
What the Data Reveals About Flag Behavior
First, the good news. The year 2025 had the lowest average number of caller ID flags per client, suggesting that businesses have finally implemented better calling practices, such as lead list auditing and STIR/SHAKEN attestation. As a result, some companies may be seeing improved call answer rates than in previous years.
That said, our report also reveals that call flags spike during certain events. For example, flags surged after the Federal Communications Commission (FCC) proposed a consent revocation rule in April 2025, which would make it easier for consumers to stop receiving telemarketing calls. We also found that flags rose during the government shutdown in fall 2025. Spam activity increased in this period, which may have caused carriers to tag more numbers.
“These patterns reinforce that caller ID reputation doesn’t change gradually — it reacts to external pressure,” says Levi Chang, CFO of CIDR. “Regulatory uncertainty, social changes, and major events all show up quickly in the data.”
How Do Flag Spikes Affect Businesses?
A temporary spike in flags because of a new regulation or an increase in spam calls can hit your business hard. Carriers and call-filtering systems can flag legitimate numbers, like the ones you use, which can result in fewer customers answering your calls. This can make it more difficult for agents to do their jobs and potentially affect sales and sign-ups.
How Consumers Influence Call Labels
One of the biggest findings from our report is that consumers often determine how calls are labeled. While phone numbers can be flagged for various reasons, 50% of all call flags in 2025 originated from consumers marking calls as spam, primarily through call-blocking apps and data aggregators. Unfortunately, many legitimate numbers are flagged during the process, potentially leaving businesses like yours unable to contact customers.
We also discovered that some numbers never get flagged throughout their lifecycle, while others receive flags every month. Dialing behavior may play a role here. For example, how often a business calls customers (calling cadence) might influence whether consumers report its calls as spam in call-blocking apps. Other factors that can lead to flags include calling customers at the wrong times and failing to update contact lists.
Does Call Remediation Actually Help?
According to our data, yes. Businesses that used CIDR’s Remediation Managed Services (RMS) experienced a reduction in flag rates over one- and two-year periods compared to businesses that just relied on our call monitoring platform. Remediation is the ongoing process of identifying incorrectly labeled call labels and working with carriers and other third parties to correct them.
Our remediation service corrects wrongly-labeled flags, on average, within 24 hours of submission. As a result, it may improve a company’s reputation with call-blocking apps and data aggregators.
Phone Number Reputation Requires Ongoing Management
Another finding from our report is that phone number reputation isn’t something you can fix once or permanently control. Instead, businesses need to monitor consumer feedback, dialing behavior, and compliance posture over time. Phone number reputation behaves like a living system that constantly evolves.
“Flags are a fact of life,” says Chang. “The goal isn’t perfection — it’s visibility, faster responses, and better decisions. Organizations that understand this are raising the odds of successful connections, not chasing the illusion of total control.”
Managing phone number reputation might involve adjusting call frequency, avoiding calling numbers on the Do Not Call Registry, and complying with laws such as the Telephone Consumer Protection Act (TCPA). Businesses should also respond to call flags quickly and ensure numbers are corrected.
Call With Confidence
The data in our report shows that businesses that engage in ongoing monitoring and remediation successfully identify flags and respond to them more quickly.
CIDR’s complete call optimization platform continuously monitors your caller IDs across carriers, call blocking apps, and aggregator APIs, helping protect your numbers from unwanted and potentially damaging flags. This way, you can reach customers without worrying about calls being marked as spam.
Want to futureproof your business against call flags? Get started with CIDR today, or learn more about flag behavior by reading the full version of our report.
Trusted by carriers and built for compliance, CIDR is the only platform you need for proactive phone number reputation management in 2026 and beyond.
