How does the STIR/SHAKEN protocol work?

STIR/SHAKEN uses digital certificates based on common public key cryptography techniques to ensure the calling number is secure and combats caller ID spoofing on public telephone networks. Through the handoff of phone calls passing through the complex web of networks, it allows for the carrier of the party receiving the call to verify that a call is in fact from the number displayed on Caller ID. In short, it verifies the authenticity of the call.


STIR is short for Secure Telephony Identity Revisited.

SHAKEN is short for Signature-based Handling of Asserted information using tokens.


Why certify my numbers with STIR/SHAKEN?


STIR/SHAKEN is a carrier-based Caller ID authentication standard that helps to verify that a call is in fact from the number displayed on the Caller ID and not being spoofed. STIR/SHAKEN technology helps to ensure that calls from Ring.io are actually from whom they say they are and reduce fraudulently spoofed calls.

Ring.io uses STIR/SHAKEN technology which may reduce the chances of calls being incorrectly marked as 'Spam' or 'Scam Likely'. Carriers do not block calls based on STIR/SHAKEN data alone but is another metric into our call analytics platform.


How the receiving carrier attests the validity of a number


The originating carrier checks the call source and calling number to determine how to attest for the validity of the calling number. Attestation is a three level system that characterize a caller’s right to use a particular number.

Full Attestation (A) — The service provider has authenticated the calling party and they are authorized to use the calling number. An example of this case is a subscriber registered with the originating telephone service provider’s softswitch.

Partial Attestation (B) — The service provider has authenticated the call origination, but cannot verify the call source is authorized to use the calling number. An example of this use case is a telephone number behind an enterprise PBX.

Gateway Attestation (C) — The service provider has authenticated from where it received the call, but cannot authenticate the call source. An example of this case would be a call received from an international gateway.

What information is needed to certify numbers with STIR/SHAKEN?

Send an email to support@ring.io with the following information.

Legal Business Name:
Business Address:
Business Type: Is your business a (Sole Proprietorship, Partnership, Corporation, co-op, LLC or non-profit)
Business Industry:
Business Tax ID:
Contact Full Name:
Contact Email:
Contact Title:
Contact Phone Number:
Business website address:
The Ring.io phone numbers that need to be certified with STIR/SHAKEN:



Frequently Asked Questions about STIR/SHAKEN

Is there a cost to certify my number(s) with STIR/SHAKEN?

Ring.io offers STIR/SHAKEN certification to all of our paid subscribers at no additional cost!


Will STIR/SHAKEN guarantee that my calls will no longer be marked as 'Spam' or 'Scam Likely?


The short answer is No. There is never a guarantee that your number will not be flagged as spam. A-Level Attestation comes in through the SIP network and terminates at the device of the receiving party. A-Level Attestation is one of many data points terminating providers consider when displaying a call.

A data point taken that is also taken into consideration comes at the analytics level, which is a separate layer outside STIR/SHAKEN Attestation and influences the call display on mobile devices. These analytics assess your phone number's reputation outside of the STIR/SHAKEN framework, which is where ‘Spam’ or ‘Scam’ labeling comes from. A-Level Attestation does not necessarily influence the presentation of Spam or Scam labeling as the technologies are not currently integrated.

If your number is still being flagged after being certified with STIR/SHAKEN, we recommend adding the number(s) to the Free Caller Registry database.

What happens after we provide all the information your carrier requires?

Our team will create a unique profile using the business information provided. Once the profile has been created and approved, the phone numbers will be added to the STIR/SHAKEN table. This process should take no more than 5 business days. The Ring.io team will keep you updated throughout the entire process.

If you have further questions about STIR/SHAKEN, please contact our support team by email at support@ring.io or by phone at 888-727-5776.


My numbers have been registered with STIR/SHAKEN but my calls are still being flagged as 'Spam' or 'Scam Likely'.

If outbound calls are still being flagged as spam, consider having the number remediated across all major carriers. Learn more about remediation here.

Can we just replace our Ring.io company and Personal number?


‍Yes, your Ring.io company and personal numbers can be replaced at anytime, but there is no guarantee that the replacement number will not be flagged. The best practice before assigning a new number to your account is to perform a reverse lookup to obtain a history of how the number has been used. Once you have decided on your new company and personal numbers, we strongly recommend certifying your numbers with STIR/SHAKEN.



Can we register STIR/SHAKEN for our RingLocal numbers?


STIR/SHAKEN can only be registered with Ring.io Personal and Company numbers. If you are using our RingLocal service, we are not able to register the numbers in the pool for STIR/SHAKEN.

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