Source note · Troubleshooting SIP 403 Forbidden from a carrier
Telnyx returns 403 with cause code D25 when it cannot locate the account or number from the source IP and username, and with D29 when the INVITE carries an invalid X-Telnyx-Token or IP.
Checked 2026-09-30
- Vendor
- Telnyx
- Product
- SIP Trunking
- Subsystem
- connection authentication
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-09-30
- Checked
- 2026-09-30
Sources
- Telnyx SIP Response Codes — Telnyx · tier 2 current vendor documentation · 403 list, cause codes D25 and D29
Cite this note
APA
WarmTransfer. (2026, September 30). Troubleshooting SIP 403 Forbidden from a carrier: source note sip-403-forbidden-troubleshooting-telnyx-d25-d29. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-403-forbidden-troubleshooting-telnyx-d25-d29
BibTeX
@misc{warmtransfer-claim-sip-403-forbidden-troubleshooting-telnyx-d25-d29,
title = {Troubleshooting SIP 403 Forbidden from a carrier: source note sip-403-forbidden-troubleshooting-telnyx-d25-d29},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-403-forbidden-troubleshooting-telnyx-d25-d29},
note = {Source note sip-403-forbidden-troubleshooting-telnyx-d25-d29, checked 2026-09-30}
}