Telnyx SIP Response Codes

Publisher

Telnyx

URL

https://support.telnyx.com/en/articles/4409457-telnyx-sip-response-codes

Published

unknown

Updated

unknown

Accessed

2026-09-30

HTTP status

200

License

proprietary; all rights reserved; no-redistribution; short excerpts and locators only

Source notes citing this source

• The bare 403 status does not identify the cause on the carriers examined: Twilio distinguishes causes by reason phrase, Telnyx by a cause code appended to the reason phrase, and Microsoft by a separate Microsoft response code, so triage should start from that qualifier rather than from the number 403. inferred in context
• Telnyx uses 403 for concurrent-call limit violations: D1 for the user channel limit, D2 for the outbound profile channel limit, D3 for the connection channel limit and D22 for any of those channel limits. in context
• Telnyx rejects an outbound call with 403 and cause code D13 when the dialed number is not in a country whitelisted in the outbound voice profile; the fix is to add the destination country to that profile's whitelist. in context
• Telnyx returns 403 with cause code D24 when the dialed destination's rate per minute exceeds the maximum rate per minute set on the outbound voice profile. in context
• 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. in context
• Telnyx rejects an outbound call with 403 and cause code D35 when the caller ID in the INVITE is not valid; the fix is to send +E.164 numbers in the From, P-Asserted-Identity or Remote-Party-ID headers. in context
• Telnyx returns 403 Forbidden with cause code D36 when an outbound call uses another Telnyx user's number as caller ID. in context
• Telnyx returns 403 with cause code D39 when the user's daily spend limit for international calls has been reached. in context
• Telnyx returns 403 with cause code D41 when the dialed number matches a forbidden prefix used for fraud prevention and with D58 when the destination number is restricted; both direct the customer to Telnyx support. in context
• Telnyx returns 403 with cause code D46 when the originating number is listed in a do-not-originate registry, meaning a number meant only to receive inbound calls was used to place an outbound call. in context
• Telnyx rejects an outbound call with 403 and cause code D51 (Unverified origination number) when the caller ID is a non-Telnyx number that has not been verified. in context
• Telnyx returns 403 with cause code D54 (Restricted origination number) when the originating caller ID is restricted from placing outbound calls through Telnyx because of reputation concerns and risk validations; the remedy is to contact support. in context
• Telnyx returns 403 when the outbound profile is disabled (D15), the SIP connection is disabled (D16) or the account is disabled (D17), and when the connection has no outbound profile assigned (D7 and D38). in context
• Telnyx returns 403 Forbidden to a REGISTER whose authentication username is empty (R14), has invalid characters (R16), is shorter than four characters (R17) or does not match the To and From user parts (R18). in context

Cite this source record

APA

WarmTransfer. (2026, September 30). Telnyx SIP Response Codes. WarmTransfer. https://warmtransfer.net/knowledge/sources/telnyx-support-sip-response-codes

BibTeX

@misc{warmtransfer-telnyx-support-sip-response-codes,
  title  = {Telnyx SIP Response Codes},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/sources/telnyx-support-sip-response-codes},
  note   = {Telnyx, accessed 2026-09-30}
}