Reputation Scores, SPAM Labels, and Call Behavior

Introduction 

Call reputation and SPAM labeling have become critical components of modern telecom security. Carriers rely on analytics engines to detect fraudulent calling patterns and protect end users. While these systems improve overall network safety, your legitimate business calls may sometimes be mislabeled as “SPAM Likely,” “Scam Likely,” or be blocked entirely. 

This guide explains what reputation scores are, how they are assigned, why SPAM labels occur, and what steps you can take to improve your number’s reputation. 

What Are Reputation Scores? 

Reputation scores are assessments assigned to phone numbers by third‑party analytics providers such as TNS Guardian and Hiya. These services evaluate calling behavior across the telecom ecosystem to identify activity that resembles spam or fraud. 

How Scores Work 

Reputation scores typically range from +4 to –4: 

• +4 → Excellent reputation, considered safe 

• 0 → Neutral 

• –3 or –4 → High‑risk behavior, often labeled as SPAM or blocked 

These scores influence whether the terminating carrier flags your call with a warning label or rejects it outright. This behavior aligns with industry practices documented by partners like Peerless, who block calls with reputation scores of –3 or –4 under their TNS Call Guardian integration.  

What Triggers Low Scores? 

Analytics platforms look for calling patterns that resemble spam behavior, such as: 

• High call volumes in short periods 

• Repeated calls to the same number 

• Many back‑to‑back calls to different numbers 

• Irregular or non‑human calling patterns 

Internal investigations of customer call logs have shown that extremely high frequency dialing such as a number placing hundreds of calls per day or dozens of consecutive attempts can negatively impact reputation. frequency dialing such as a number placing hundreds of calls per day or dozens of consecutive attempts can negatively impact reputation.  

How Reputation Scores Are Assigned 

Reputation scores are not created by CallTower or by the carrier hosting your phone numbers. Instead, major carriers like Verizon, AT&T, and T‑Mobile rely on independent analytics engines such as TNS Guardian and Hiya to determine the risk profile of a number.  

These systems: 

• Aggregate data from many carriers and networks 

• Use machine learning and industry‑wide call analysis 

• Assign organization‑level scores even before a number of builds history 

This means: 

• A newly ported number can temporarily start with a low reputation  

• High‑risk behavior from any number within a business may influence the overall organizational score. 

What CallTower Can and Cannot Control 

✔️ What CallTower Can Do 

• Ensure your CNAM is properly updated in national databases. 

• Verify your outbound routing configuration is correct. 

• Provide guidance on industry best practices. 

• Review attestation levels to ensure we are sending out the highest trust level.  

• Review call logs for potential behavior affecting reputation.  

❌ What CallTower Cannot Control 

• How a carrier evaluates your number or organization 

• Whether a carrier marks your calls as SPAM 

• How quickly carriers update their CNAM or reputation data 

• The internal algorithms used by TNS, Hiya, or other analytics partners 

Register Your Numbers with Major Carriers 

Carriers provide online tools for businesses to verify and register their phone numbers. Registering helps ensure that your calls are recognized as legitimate. 

General Resources 

• Call Transparency 

• Free Caller Registry 

• Voice Spam Feedback 

• Report a Robocall 

Carrier-Specific Resources 

• Verizon: Voice Spam Feedback 

• T-Mobile: T-Mobile Call Reporting 

• AT&T: AT&T Support via Hiya 

What is CNAM? 

CNAM (Caller Name) is the display name that appears on the recipient's phone when you make a call. It typically includes your business name or department. This information is not stored or broadcast by CallTower directly—rather, it's pulled from databases managed by receiving carriers and third-party providers. 

Steps to Set up or Update CNAM 

1. Determine the Numbers You Want to Update 

• Identify which DIDs (Direct Inward Dialing numbers) you want to associate with a business name or department label. 

2. Contact CallTower Support 

• Send an email to support@calltower.com with the following information: 

1. A list of DIDs requiring CNAM updates 

2. The exact CNAM you want displayed for each number (Max 15 characters) 

3. Understand CNAM Formatting Requirements 

• Character Limit: Most carriers restrict CNAM to 15 characters, including spaces. Anything longer may be truncated. 

• Use easily recognizable identifiers (e.g., ACME SALES, ACME SUPPORT) 

• Avoid special characters and abbreviations that may confuse recipients 

• Ensure consistency across all numbers used for outbound calling 

4. Recognizing Carrier Limitations 

• Not all carriers support CNAM display in the same way. 

• Mobile carriers may override CNAM with their own spam scoring or caller ID apps (e.g., Hiya, Truecaller). 

5. Allow Time for Propagation 

• After submitting your request, it may take several business days (up to weeks or months for rural municipalities) for CNAM updates to propagate across various national databases used by carriers.