Call_ended Webhook Not Firing for IVR-Forwarded Calls to Retell-Twilio Number

Support Help
1

[Bug/Issue] call_ended webhook & transcript missing for calls forwarded via IVR to Retell-connected Twilio number

Summary

When an inbound call hits our IVR number and gets redirected to our Retell-connected Twilio number, the call functions correctly (AI agent responds, conversation happens normally), but:

  • call_ended webhook is never fired
  • Call transcript is never generated
  • The call_id from call_started does not appear in the Retell dashboard
  • The call is only visible in Twilio dashboard with the correct duration (via Twilio SID)

Direct calls to the Twilio/Retell number work perfectly — call_started, call_ended, transcript, and dashboard entry all behave as expected.

Setup

  • Inbound calls arrive on our IVR number
  • IVR redirects/forwards the call to our Twilio number which is connected to Retell
  • Twilio is configured via SIP trunk pointing to Retell

Observed Behavior (Forwarded Call)

Event Status
call_started webhook :white_check_mark: Received
AI agent responds on call :white_check_mark: Working
call_ended webhook :cross_mark: Never received
Transcript :cross_mark: Not generated
Call visible in Retell dashboard :cross_mark: Not visible
Call visible in Twilio dashboard :white_check_mark: Visible with correct duration

Observed Behavior (Direct Call)

Everything works as expected — call_started, call_ended, transcript, and dashboard entry all appear correctly.

What We’ve Checked

  • Our webhook endpoint returns 2xx responses within the timeout window — confirmed via logs
  • No webhook retries observed for call_ended (it simply never arrives)
  • Twilio SIP trunk is correctly configured and pointing to sip.retellai.com
  • The call_id received in call_started cannot be found anywhere in the Retell dashboard

Ask

  1. Is IVR call forwarding to a Retell-connected Twilio number a supported flow?
  2. Are there any specific SIP headers or Twilio configuration requirements needed to ensure Retell properly tracks forwarded calls end-to-end?
  3. Is there a known workaround or recommended architecture for this IVR → Retell pattern?

Happy to share call IDs, Twilio SIDs, or webhook logs if it helps the team investigate.

Thanks!

2

Thank you for reaching out to Retell AI Support. We’ve received your ticket and our team will respond within 8 hours.

3

Hi Retell,

Hi there,
To assist with your Retell AI integration, please review the following resources:

Best,
Evy AI
AI Support Agent @ Retell AI

4

Hello @karanchugh02

Please share the call ids

5

call_53ccca72566f542046e6c8fac10
call_6760cb5c91e2046c486817b11c2
call_5e91d659269b7bf1ec64f01fd79

These are few of the call ids related to this issue, there are several other as well.

6

I can’t find calls with these call IDs. Can you share how you got them? Do they show up on the Retell AI dashboard?

7

This is the point @Omar_Ashraf , I am receiving these id’s in webhook calls. I am also able to talk with the AI, the calls are visible in twilio dashboard but in retell there’s no sign of these calls

8

I’ve forwarded this to the product team

Can you share the call IDs from Twilio?