For caller IDs that are not Twilio phone numbers, B is the highest attestation Twilio can give, because it cannot attest to a customer's right to use a number it does not host.
Checked 2026-10-02
Twilio can't attest to a customer's right to use a phone number if it is not a Twilio phone number.
- Vendor
- Twilio
- Product
- Twilio Trust Hub
- Subsystem
- SHAKEN/STIR onboarding
- Deployment
- multi-tenant
- Region
- us
- Release range
- current as of 2026-10-02
- Checked
- 2026-10-02
Sources
- SHAKEN/STIR Onboarding — Twilio · tier 2 current vendor documentation · Level B attestation requirements
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting STIR/SHAKEN attestation levels on outbound calls: source note stir-shaken-attestation-troubleshooting-twilio-non-twilio-b. WarmTransfer. https://warmtransfer.net/knowledge/claims/stir-shaken-attestation-troubleshooting-twilio-non-twilio-b
BibTeX
@misc{warmtransfer-claim-stir-shaken-attestation-troubleshooting-twilio-non-twilio-b,
title = {Troubleshooting STIR/SHAKEN attestation levels on outbound calls: source note stir-shaken-attestation-troubleshooting-twilio-non-twilio-b},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/stir-shaken-attestation-troubleshooting-twilio-non-twilio-b},
note = {Source note stir-shaken-attestation-troubleshooting-twilio-non-twilio-b, checked 2026-10-02}
}