Hi — I found guidance suggesting that inbound webhooks may not work properly on Twilio SIP trunk imported numbers.
That appears to match our issue exactly.
Our setup:
- Twilio number
- connected to Retell via Twilio SIP trunk / imported number flow
- outbound calls work
- inbound callback detection logic works in our backend
- inbound webhook responds correctly with callback-aware values
- but the live inbound callback call still does not use the correct inbound callback opener
What I need confirmed:
- Do inbound webhooks fully work on Twilio SIP trunk imported numbers?
- If not, is this a known limitation?
- If it is a limitation, what is the recommended supported workaround for missed-call callback routing on imported Twilio SIP numbers?
- Should we instead use SIP headers / another inbound configuration method for callback state?
- If inbound webhook overrides are unsupported on this number type, is buying/using a Retell-native number the only reliable way to get this behavior?
If helpful, I can provide:
- webhook payload
- webhook response
- example transcript
- exact call behavior
- screenshots from CRM and Retell