Phone numbers sent to Twilio over SIP must be E.164-formatted, such as +12128675309, or Twilio rejects the call with SIP 400 Bad Request.
Checked 2026-09-24
If E.164 format is not used, then the call will be rejected with a SIP 400 Bad Request response.
- Vendor
- Twilio
- Product
- Elastic SIP Trunking
- Subsystem
- termination
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-09-24
- Checked
- 2026-09-24
Sources
- Elastic SIP Trunking — Twilio · tier 2 current vendor documentation · Termination (E.164 note)
Cite this note
APA
WarmTransfer. (2026, September 24). Setting up an Asterisk PBX with Twilio Elastic SIP Trunking: source note asterisk-twilio-pbx-setup-e164-required. WarmTransfer. https://warmtransfer.net/knowledge/claims/asterisk-twilio-pbx-setup-e164-required
BibTeX
@misc{warmtransfer-claim-asterisk-twilio-pbx-setup-e164-required,
title = {Setting up an Asterisk PBX with Twilio Elastic SIP Trunking: source note asterisk-twilio-pbx-setup-e164-required},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/asterisk-twilio-pbx-setup-e164-required},
note = {Source note asterisk-twilio-pbx-setup-e164-required, checked 2026-09-24}
}