The Silent Problem Costing Businesses Thousands of Calls
Most business leaders assume their outbound calls are reaching customers. They invest in sales teams, refine scripts, and optimize CRM workflows, while quietly losing a significant percentage of calls before the phone rings twice.
The reason is rarely what they expect. It is not spam behavior, aggressive dialing, or consumer complaints. In many cases, it is an obscure federal framework called STIR/SHAKEN, and most businesses have never heard of it.
STIR/SHAKEN is the call authentication standard mandated by the FCC and implemented across US carrier networks. It determines whether your business calls are verified, partially verified, or unverified — and that determination directly shapes what recipients see on their screens before they decide to answer.
The team at Likely A Business has documented how attestation level directly determines which label recipients see before answering. For businesses that rely on outbound calling — sales, appointment reminders, customer service follow-ups — that label is the difference between a conversation and a missed opportunity.
What STIR/SHAKEN Actually Does
STIR stands for Secure Telephone Identity Revisited. SHAKEN stands for Signature-based Handling of Asserted information using toKENs. Together, they form a digital certificate framework that travels with every call through the US telephone network.
When your business places an outbound call, your originating carrier evaluates whether it can verify two things: that the call is coming from a legitimate source, and that you are authorized to use the number displayed as your caller ID. Based on that evaluation, your carrier assigns an attestation level and signs the call with a digital certificate.
That signed certificate passes through the network and is read by the recipient’s carrier, which uses it, alongside its own analytics, to decide how to label your call on the recipient’s screen.
The Three Attestation Levels — And Why They Matter
STIR/SHAKEN uses three attestation levels, referred to as A, B, and C. Understanding the difference is essential for any business that depends on call-based communication.
Full Attestation (A) is the highest level. It means the originating carrier has verified that the caller is a legitimate customer, that the customer is authorized to use the number being displayed, and that the call originated on their network. Calls with A-level attestation are treated as verified and are far less likely to be flagged or labeled negatively.
Partial Attestation (B) means the carrier can verify the call’s origin on their network but cannot confirm that the caller is authorized to use the displayed number. This often occurs when businesses use third-party telephony providers or complex VoIP configurations. B-level calls carry more risk of being flagged.
Gateway Attestation (C) is assigned when a carrier can verify only that the call entered the US network at a specific point, typically from an international or unknown origin. C-level calls are treated with the highest suspicion and are most likely to trigger negative labels.
The practical consequence is straightforward: businesses receiving A-level attestation enjoy the highest credibility in carrier analytics systems. Businesses stuck at B or C level, often without knowing it, face elevated risk of “Spam Likely,” “Scam Likely,” or generic negative labels appearing on recipient screens.
How Attestation Level Connects to Real-World Labeling
Attestation is one input into a larger carrier analytics system. Major US carriers and analytics providers, including STIR/SHAKEN participants like TransUnion, Hiya, and First Orion, combine attestation data with call behavior patterns, consumer feedback, and registration data to generate the final label displayed to recipients.
A business with A-level attestation that also dials at high volume without proper registration may still receive negative labels. Attestation is necessary but not sufficient. However, businesses operating at B or C level start every call at a disadvantage, and that disadvantage compounds quickly at scale.
For businesses placing hundreds or thousands of outbound calls per month, even a modest reduction in answer rates, driven by negative labeling, translates directly into lost revenue, missed appointments, and degraded customer relationships.
What Businesses Should Do Now
Fixing your STIR/SHAKEN position requires addressing the root causes of lower attestation, not just the symptoms.
Audit your current attestation level. Ask your telephony provider what attestation level your calls are receiving. If they cannot tell you, that is itself a problem worth addressing.
Align your number registration. Ensure your business numbers are registered with the Free Caller Registry (freecallerregistry.com) and that your CNAM (Caller Name) data accurately reflects your business identity. Mismatches between registration data and call behavior are a primary driver of poor attestation.
Evaluate your telephony infrastructure. If you are using VoIP providers, SIP trunks, or third-party dialing platforms, confirm that your provider supports full STIR/SHAKEN attestation for your specific configuration. Many businesses discover they are receiving B-level attestation simply because their provider cannot verify number ownership.
Review your call behavior patterns. High call volume, irregular dialing hours, and low answer-to-call ratios all feed into carrier analytics. Attestation alone will not override behavioral signals that trigger spam classification.
For a comprehensive overview of the remediation pathway, the STIR/SHAKEN compliance guide at Likely A Business covers the full process in practical terms.
The Bottom Line
STIR/SHAKEN was designed to protect consumers from fraudulent and spoofed calls. That is a legitimate and important goal. But the framework has introduced a secondary consequence: legitimate businesses are being filtered by the same systems designed to stop bad actors, often without any awareness that it is happening.
Understanding attestation levels, auditing your telephony infrastructure, and taking deliberate steps to establish caller ID credibility are no longer optional for outbound-dependent businesses. They are foundational to protecting your ability to reach the customers you are trying to serve.
