Who Decides Your Number is Spam in the USA?
The complete guide to FCC, carriers, analytics providers, and STIR/SHAKEN
THE SHORT ANSWER
In the United States, no single entity decides if your number is spam. It's a complex ecosystem involving federal regulators (FCC & FTC), major carriers (Verizon, AT&T, T-Mobile), analytics providers (Hiya, TNS), consumer apps, and the STIR/SHAKEN protocol. Each player contributes to your number's reputation score, and any one of them can torpedo your answer rates.
The 5 Spam Decision Makers
1. Federal Regulators
FCC mandates STIR/SHAKEN and sets robocall rules. FTC enforces the Do Not Call Registry and prosecutes illegal telemarketers.
2. Major Carriers
Verizon, AT&T, and T-Mobile implement call labeling and blocking at the network level. They control what 300M+ Americans see on their screens.
3. Analytics Providers
Hiya, TNS (Transaction Network Services), and First Orion power carrier spam detection. They analyze billions of calls to build reputation scores.
4. Consumer Apps
Truecaller (300M users), Nomorobo, RoboKiller, and Hiya app let users report and block numbers. Their databases influence carrier decisions.
5. STIR/SHAKEN Protocol
The FCC-mandated caller ID authentication system. Verifies calls haven't been spoofed and assigns attestation levels (A, B, or C).
The US Regulatory Framework
FCC
Federal Communications Commission
- Mandates STIR/SHAKEN caller ID authentication
- Authorizes carriers to block illegal robocalls
- Enforces TCPA (Telephone Consumer Protection Act)
- Issues fines up to $10,000+ per illegal call
FTC
Federal Trade Commission
- Manages the National Do Not Call Registry
- Enforces TSR (Telemarketing Sales Rule)
- Prosecutes deceptive telemarketing practices
- Can seek civil penalties and injunctions
Key Laws You Must Know
TCPA
Requires prior express consent for autodialed calls/texts. Violations: $500-$1,500 per call in private lawsuits.
TSR
Prohibits deceptive telemarketing, requires DNC compliance, bans abandoned calls. FTC enforcement.
TRACED Act (2019)
Mandated STIR/SHAKEN adoption, extended statute of limitations, increased FCC fine authority.
The Carrier Ecosystem
Major US carriers control what 300+ million Americans see when your number calls. Here's who powers their spam detection.
| Carrier | Spam System | Subscribers | Impact Level |
|---|---|---|---|
| Verizon | Call Filter (Hiya-powered) | 120M+ | Very High |
| AT&T | ActiveArmor (Hiya-powered) | 100M+ | Very High |
| T-Mobile | Scam Shield (TNS-powered) | 100M+ | Very High |
| US Cellular | Call Guardian (TNS-powered) | 5M+ | Moderate |
Hiya Analytics
Powers Verizon Call Filter, AT&T ActiveArmor, Samsung Smart Call. Analyzes 40B+ calls/year.
Transaction Network Services
Powers T-Mobile Scam Shield, US Cellular. Maintains call behavior analytics for 2B+ phone numbers.
First Orion
Powers smaller carriers and offers "Branded Caller ID" for businesses to display names/logos.
STIR/SHAKEN: The Authentication Layer
The FCC-mandated protocol that verifies caller ID authenticity
Full Attestation
Carrier verifies the caller has the right to use the number. Best reputation.
Partial Attestation
Carrier knows the customer but can't verify they own the number. Moderate trust.
Gateway Attestation
Carrier can't verify origin (international, VoIP gateway). High spam suspicion.
Why STIR/SHAKEN Matters for Your Business
Calls with "C" attestation are 3x more likely to be labeled as spam
"A" attestation significantly improves answer rates (up to 30% higher)
VoIP and international calls often default to "B" or "C" attestation
Work with your carrier/provider to ensure proper attestation levels
Timeline of a Spam Flag
First user reports your number via carrier app or Truecaller. Report enters analytics database.
Alert threshold reached - Under review
Analytics provider assigns 'Spam Likely' or 'Scam Likely' label. Carriers begin displaying warnings.
Number potentially blocked by default on some networks. Answer rates plummet to <5%.
Decision Power Ranking
| Decision Maker | Impact | Why |
|---|---|---|
| Major Carriers (Verizon, AT&T, T-Mobile) | Control call display for 300M+ subscribers. Can silently block calls before they ring. | |
| Analytics Providers (Hiya, TNS, First Orion) | Power carrier spam detection. A negative score here affects all carrier networks. | |
| STIR/SHAKEN Attestation | Low attestation = automatic suspicion. Essential for call authentication credibility. | |
| Consumer Apps (Truecaller, Nomorobo) | Large user bases but limited to app users. Growing influence on carrier databases. | |
| FCC/FTC Regulators | Set rules but don't block individual calls. Enforcement is reactive, not preventive. |
Can You Contest a Spam Label?
With Carriers
Each major carrier has a dispute process. Verizon, AT&T, and T-Mobile have online portals to request number reputation review. Process typically takes 2-4 weeks but success rate varies.
- - Verizon: hiya.com/verizon-number-lookup
- - AT&T: hiya.com/att-number-lookup
- - T-Mobile: business.t-mobile.com
With Analytics Providers
Since Hiya and TNS power multiple carriers, fixing your reputation with them can have broader impact. Most offer enterprise registration programs for legitimate businesses.
- - Hiya: business.hiya.com/number-registration
- - TNS: tnsi.com/products/caller-identity
- - Free Caller Registry: freecallerregistry.com
Prevention is always easier than remediation. Monitor your numbers proactively.
Consumer Apps: The User-Driven Layer
Truecaller
300M+ users worldwide
Community-driven database. Users can report and identify numbers.
Hiya App
50M+ downloads
Consumer app from the analytics giant. Data feeds back to carrier systems.
Nomorobo
Landline + Mobile
FTC award winner. Blocks robocalls at the network level for many VoIP providers.
RoboKiller
12M+ users
Uses "answer bots" to waste scammer time. Premium spam blocking.
Frequently Asked Questions
Does the FCC directly block spam calls?
How does STIR/SHAKEN affect my business calls?
Can I sue someone for reporting my number as spam?
Are spam databases shared between carriers?
What's the difference between TCPA and TSR violations?
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