frequent outbound call fail during transfer

Support Help
1

At the time of this posting, I’m currently putting my phone into production and I’m having issues with inconsistent forwarding failures. is anybody else having intermittent issues by chance?

2

Yes, others have reported intermittent call forwarding issues with Retell AI.(1)(2)

Known Issues:

Users have experienced intermittent call transfer failures where approximately 20% of transfers fail without configuration changes.(1) Another reported issue involves the system rejecting valid E.164 numbers intermittently, claiming “Transfer destination number is not a valid e.164 number” even though the same number works successfully in other calls.(2)

Common Failure Scenarios:

When call transfer is triggered but fails, common causes include:(3)

  • Telephony issues: Call transfer failures occur for similar reasons as outbound call failures, with SIP connection logs available in call logs for diagnosis(3)
  • Could not detect human: If human detection is enabled, the call may fail if a human is not successfully detected(3)

Troubleshooting Steps:

For Single/Multi-Prompt Agents, verify your transfer_call function is properly added to your agent’s function list and that transfer conditions are clearly defined in your agent’s prompt.(3)

For Conversation Flow Agents, check that your transfer node is properly configured, connected to other nodes, and that transition conditions are correctly set up.(3)

Important Note: Call transfer is only supported for phone calls, not web calls.(3)

Check your call’s disconnection_reason field through the Retell Dashboard or the get-call API endpoint to diagnose the specific failure reason.(4)

3

Hello @Chris_Fairfield

Can you share the call IDs of these failures?

4

I don’t have information about specific call failures or call IDs from your account based on the available sources. To retrieve call IDs and details about failed calls, you can use the List Calls API(1).

You can filter calls by status and other criteria using the filter_criteria parameter(1). For example, to find calls with error status:

{  
  "filter_criteria": {
    "call_status": ["error"]
  }
}

(1)

Each call response will include a call_id field that uniquely identifies the call(1), (2). You can also check the disconnection_reason field to understand why calls failed(1), (2).

If you need assistance identifying specific failed calls from your account, I recommend: