STIR/SHAKEN: What It Is and Why It Matters for Your Business
STIR/SHAKEN is a technology framework designed to reduce fraudulent robocalls and illegal phone number spoofing. For business owners, the goal is simple: make it easier to trust that incoming calls are from who they say they are, and make it harder for scammers to hide behind fake caller ID.
The Problem STIR/SHAKEN Tries to Solve
Spam and illegal robocalls have been a major problem for years. In 2019, phone calls were the most common way scammers reached their victims. When people cannot trust that callers are who they claim to be, they start ignoring calls altogether, even from legitimate businesses.
That is bad for everyone. Customers miss important calls. Businesses see lower answer rates. And scammers keep exploiting the system. STIR/SHAKEN was created to help restore trust in caller ID so people feel more comfortable answering the phone.
What Is STIR?
STIR stands for Secure Telephony Identity Revisited. It is a working group within the IETF that developed a set of protocols used to create a digital signature for a call.
When a call is placed, the originating carrier can add a signed SIP header that includes information about the calling party. The terminating provider can then verify that signature before completing the call. In simple terms, STIR adds a “security stamp” to the call that proves which carrier started it and whether the caller ID is legitimate.
What Is SHAKEN?
SHAKEN stands for Secure Handling of Asserted information using tokens. It defines the standards for how STIR is deployed by service providers within their networks.
Together, STIR and SHAKEN create a framework where calls traveling through interconnected phone networks can have their caller ID “signed” as legitimate by originating carriers and validated by other carriers before reaching consumers.
How Does STIR/SHAKEN Work?
STIR/SHAKEN uses public key cryptography and digital certificates to authenticate phone calls, similar to how e-commerce websites secure their traffic.
The process works like this:
The originating carrier checks the call source and calling number.
It generates a secure SIP identity header with an attestation level.
That header is digitally signed using a certificate from a trusted certificate authority.
The terminating carrier verifies the signature before delivering the call.
This does not block calls by itself. Instead, it gives carriers more information about whether a call’s caller ID can be trusted, which they can use to decide how to handle the call.
How Does This Help You?
For business owners and managers, the main benefit is trust. When your outbound calls are properly signed, receiving carriers can see that your caller ID is authenticated. That can help reduce the chance that your legitimate calls are marked as spam or ignored.
On the inbound side, STIR/SHAKEN helps your team and customers feel more confident about answering calls. You should not notice any functional change to caller ID displays, other than the ability to better trust the data you see.
How Does STIR/SHAKEN Stop Illegal Robocalls?
STIR/SHAKEN does not magically stop all robocalls, but it makes illegal spoofing harder and easier to trace.
By requiring carriers to sign calls and verify signatures, it becomes more difficult for bad actors to fake caller ID without being detected. It also improves traceback efforts, so regulators and carriers can more easily find where fraudulent calls enter the network.
The Federal Trade Commission has been working to educate the public about unwanted calls, but with mixed success. STIR/SHAKEN adds a technical layer to that effort by making spoofed calls easier to identify and less trustworthy to receiving networks.
What Are Attestations?
Attestation levels are like scores for a telephone call. They range from A (Full), B (Partial), and C (Gateway).
These levels tell the receiving carrier how much the originating provider knows about the caller and whether the caller is authorized to use the number. Based on these levels, carriers can decide how to treat the call, such as allowing it, flagging it, or, in some cases, blocking it.
A – Full Attestation
Full attestation means the service provider knows the customer and has the right to use the telephone number they are calling from.
This is the highest level of trust. It indicates the provider has a direct relationship with the caller and can confirm the caller is authorized to use the phone number.
B – Partial Attestation
Partial attestation means the service provider knows the customer but not the source of the telephone number they are calling from.
In this case, the provider knows who the caller is but cannot fully verify that the caller is allowed to use the specific caller ID number.
C – Gateway Attestation
Gateway attestation means the service provider has originated the call into the network but cannot authenticate the call source.
This is the lowest level of attestation. It often applies when the call comes from outside the provider’s network or from a gateway where the caller’s identity is not fully known. Calls with C attestation are more likely to be flagged or blocked as potential spam.
How Much Does STIR/SHAKEN Cost?
For Fireline customers, STIR/SHAKEN is included in your service at no extra charge. Fireline Communications does not charge separately for STIR/SHAKEN. It is already part of your plan.
Why This Matters for Your Business
If your business makes outbound calls, STIR/SHAKEN helps protect your brand from impersonation and improves the chances that your calls will be answered. Properly signed calls show receiving carriers that your caller ID is authenticated, which can reduce the risk of being labeled as spam.
If you receive a high volume of calls, STIR/SHAKEN helps you and your team better trust the caller ID you see. That makes it easier to separate legitimate calls from potential scams and reduces the risk of falling victim to spoofed numbers.
Conclusion
STIR/SHAKEN is not a perfect solution, but it is an important step toward restoring trust in phone calls. By adding digital signatures and attestation levels to calls, it makes illegal spoofing harder and gives carriers better tools to identify and trace fraudulent traffic.
For Fireline customers, STIR/SHAKEN is already built into your service with no extra cost. That means you benefit from improved caller ID authentication without having to change how you use your phone system.
Why Choose Fireline Communications?
- Same-day service replacement
- Crystal-clear call quality
- No equipment changes required
- We match your existing features
- Unbeatable pricing
We can replace your service in one day and keep your business connected without interruption.
Contact Fireline Communications today to upgrade your lines. You can also call us now! 1-877-347-3147
FAQ
What is STIR/SHAKEN?
STIR/SHAKEN is a call authentication framework that uses digital signatures and certificates to verify that caller ID information has not been spoofed.
Does STIR/SHAKEN stop all robocalls?
No. It does not block all robocalls, but it makes illegal spoofing harder and helps carriers identify and trace fraudulent calls.
What do attestation levels A, B, and C mean?
A means full attestation and highest trust, B means partial attestation, and C means gateway attestation with the lowest level of caller verification.
Will I see any changes on my phone?
You should not notice major changes to caller ID displays, but you may see improved trust in the caller ID data and better handling of suspicious calls.
Is STIR/SHAKEN required by law?
In the U.S., the TRACED Act directed the FCC to require carriers to implement STIR/SHAKEN, and most providers were required to comply by June 2022.
Does STIR/SHAKEN block calls?
No. STIR/SHAKEN itself is not a call blocking method; it authenticates calls so carriers can make more informed decisions about how to handle them.
How does this help my business outbound calls?
Properly signed outbound calls are less likely to be flagged as spam and more likely to be trusted by receiving carriers and customers.
How much does STIR/SHAKEN cost for Fireline customers?
It is free for Fireline customers. STIR/SHAKEN is already included in your service with no extra charge.
Last Updated on July 29, 2026