I AM GETTING THE TANSFER CALL FAILURE ISSUE JUST WHEN THE TOOL IS CALLED https://cdn.discordapp.com/attachments/1421383405907742781/1421383406213660692/Screenshot_2025-09-27_at_11.58.58_AM.png?ex=68d8d5f4&is=68d78474&hm=cf90f3aa2e0f1d3f51b4044bedcf2467d3367f581351a31014417b424be8456a&

Thanks for sharing the issue. To help troubleshoot, could you please confirm if you have set the required

"destination"

property (with a valid E.164 phone number) in your transfer_call_tool's parameters? This is a common cause of transfer failures. Sources: - [Vapi documentation: call forwarding](https://docs.vapi.ai/call-forwarding) - [Vapi SIP Trunking Telnyx external number call forwarding troubleshooting](https://discord.com/channels/1211482211119796234/1343963959421829172)

Hi WhilpashH, If you're setting up call forwarding using Vapi and experience issues like call drops during transfers or configuration challenges, here's a quick guide to help you troubleshoot and set up effectively: 1. Setting Up Call Forwarding: - On the Vapi dashboard, create a Transfer Call Tool. You can configure destinations with messages for guidance during the transfer. 2. Troubleshooting Call Drops: - Check the call logs for the

endedReason

to confirm if a transfer was initiated. - Ensure the

phoneCallProviderBypassEnabled

is set to

false

unless you're implementing custom transfer logic. - Verify SIP configuration if transfers involve SIP endpoints. - Use the Vapi API to investigate and ensure the assistant is not overriding call controls. Removing

"phone-call-control"

from

serverMessages

might be necessary. 3. Advanced Features: - Consider using dynamic call transfers to route calls based on conversation context or here’s a [guide on implementing dynamic transfers](https://docs.vapi.ai/calls/call-dynamic-transfers), which can help ensure calls reach appropriate departments based on real-time analysis. For specific transfer modes, such as warm transfers, ensure your configuration aligns with intended use (e.g., using

warm-transfer-experimental

mode) and verify settings like

maxDurationSeconds

to prevent abrupt cancellations. If problems persist, it might be due to provider-level issues or misconfigurations, check documentation regarding SIP configurations and API handling for deeper insights. If this doesn’t resolve the issue, please let us know and we’ll be happy to step in and assist further.