Source note · Troubleshooting SIP 403 Forbidden from a carrier
Twilio documents a '403 Phone number is blocked for verification' failure meaning Twilio has blocked the destination number, with contacting Twilio Support as the remedy if the block is unintended.
Checked 2026-09-30
- Vendor
- Twilio
- Product
- Elastic SIP Trunking
- Subsystem
- destination blocking
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-09-30
- Checked
- 2026-09-30
Sources
- Troubleshooting your Trunk — Twilio · tier 2 current vendor documentation · Termination Calls > Problem: The call fails with a '403 Phone number is blocked for verification' error
Cite this note
APA
WarmTransfer. (2026, September 30). Troubleshooting SIP 403 Forbidden from a carrier: source note sip-403-forbidden-troubleshooting-twilio-blocked-verif. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-403-forbidden-troubleshooting-twilio-blocked-verif
BibTeX
@misc{warmtransfer-claim-sip-403-forbidden-troubleshooting-twilio-blocked-verif,
title = {Troubleshooting SIP 403 Forbidden from a carrier: source note sip-403-forbidden-troubleshooting-twilio-blocked-verif},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-403-forbidden-troubleshooting-twilio-blocked-verif},
note = {Source note sip-403-forbidden-troubleshooting-twilio-blocked-verif, checked 2026-09-30}
}