Overview
Twilio Elastic SIP Trunking customers sometimes request the ability to place outbound calls without presenting a caller ID (anonymous or “no caller ID” calls). This article explains Twilio’s policy, compliance requirements, and available alternatives.
What You Need To Know
Key Points
- Twilio does not support fully anonymous outbound calling (suppression of caller ID) on Elastic SIP Trunks.
- All outbound calls must present a valid caller ID (Calling Line Identification/CLI).
- Attempts to send calls with no caller ID or blank CLI will result in the call being rejected or the CLI being replaced with a default value.
- This restriction is due to compliance and regulatory requirements.
Alternatives
If privacy is required, consider these options:
-
Use a generic or company number as caller ID:
You may configure your SIP trunk to present a valid Twilio-owned number that does not identify the individual caller. -
Leverage CNAM or Branded Calling:
Twilio offers products to brand your calls with a business name or custom caller ID.
3CX and Other PBX Providers
Some PBX providers (like 3CX) may request that the SIP trunk provider support anonymous calling. Twilio’s compliance requirements mean this is not possible; all outbound calls must have a valid caller ID.
Conclusion
Twilio Elastic SIP Trunking does not allow fully anonymous outbound calls. All calls must present a valid caller ID. For privacy, use a generic number or Twilio’s branding solutions.
Below you will find references to useful documents: