This article explains how to obtain a STIR/SHAKEN certificate and enable the related services provided by Trunking.io.
In 2021, the FCC introduced the STIR/SHAKEN requirements, and beginning in July 2025, it clarified that resellers will no longer be allowed to share certificates. Each reseller must get and use its own unique certificate to authenticate its calls. This change helps ensure accountability, so every provider in the call chain can be traced and verified, making it harder for spam or scam calls to slip through.
You need a STIR/SHAKEN certificate if you are a reseller. You do not need a STIR/SHAKEN certificate if you are an end-user and do not resell telecom services.
The call flow begins when a user places a call through their telephone service provider. The provider checks whether the calling party is actually authorized to use the specified phone number.
If everything is in order, the Authentication Service generates a digital signature, token, confirming the authenticity of the number and attaches it to the SIP-header of the call.
This signature is created using a digital certificate issued by a certification authority accredited under the STIR/SHAKEN framework. The call, now carrying the digital signature, is transmitted across the network to the Terminating Provider, the provider serving the call recipient.
The receiving provider uses a Verification Service to validate the signature. It checks the certificate against the central certificate database to ensure that the signature indeed belongs to a trusted provider and has not been tampered with.
If the verification is successful, the system marks the call as verified, and the recipient’s phone may display a message such as “Verified Caller”, “Caller Verified”, or show a shield icon.
If the signature fails verification or is missing, for example, because the certificate is expired, forged, or the call originates from a network where STIR/SHAKEN is not implemented, the call is still delivered, but it may be flagged as “Spam Likely”, “Unverified Number”, “Potential Fraud”, or something similar.
Note: if your organization does not resell telco services, you are not required to obtain a STIR/SHAKEN certificate. In this case, select the “End User” option when signing up for Trunking.io services.
The process of getting a STIR/SHAKEN certificate involves four steps: