Short answer: ElevenLabs doesn’t document any way to change or upload “hold/ringback music” for transfers. The transfer_to_number system tool only lets you set a spoken client_message that the agent says while the transfer is in progress. There’s no documented parameter for custom audio/music during the transfer.
What you can configure today
Set the spoken message the caller hears during transfer via client_message when calling transfer_to_number. (elevenlabs.io)
If you’re transferring between AI agents (not to a phone number), you can optionally set a “Transfer Message” to play during the handoff (still TTS, not music). (elevenlabs.io)
Transfers are executed over Twilio or SIP trunking; the ElevenLabs docs don’t cover custom hold music on those providers. (elevenlabs.io)
If you need true hold music: it isn’t described as supported in ElevenLabs’ docs. I’d suggest contacting ElevenLabs Support to request this feature or confirm roadmap. (help.elevenlabs.io)
References:
Transfer to human (transfer_to_number) tool and parameters (client_message, agent_message). (elevenlabs.io)
Agent-to-agent transfer (“Transfer Message”). (elevenlabs.io)
Alrgiht, please right me the mail that I will send to the support. In the questions, also include the question on how to set up the timeout for example to 20s so that the elevenlabs agent take back the call if the person didn't answer the phone.
gritty iris
finite canopy