can i add a number with an extension to the transfer_to_number tool in conversational ai agent? | ElevenLabs | Page 1

craggy spindleBOT Sep 20, 2025, 6:14 AM

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AI-generated Answer for tailwind8960

Short answer: No. The transfer_to_number tool expects a destination formatted as either:

An E.164 phone number (e.g., +12125551234), or
A SIP URI (sip:user@domain), which is only supported when using SIP REFER transfers. Extensions are not supported inline in the transfer_number value. (elevenlabs.io)

How to reach an extension:

Transfer to the main number, then have the agent send the extension via DTMF using the play_keypad_touch_tone system tool (supports digits 0–9, *, #, and pauses w/W). (elevenlabs.io)
Note: The default “Conference Transfer” removes the AI agent after connecting the other party, so any DTMF must be sent before the agent is removed, or you can use SIP REFER to transfer directly to a SIP URI that your PBX routes to the extension. (elevenlabs.io)

References:

Transfer to human (requirements and formats). (elevenlabs.io)
Play keypad touch tone (entering extensions via DTMF). (elevenlabs.io)

covert socket Sep 21, 2025, 1:04 AM

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but i am using standard twilio telephony not eh sip infrsatructure. what tod o then?

craggy spindleBOT Sep 21, 2025, 1:04 AM

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AI-generated Answer for tailwind8960

Short answer: with the native Twilio telephony integration, you can’t include an “extension” in the transfer_to_number value. You must transfer to the main E.164 phone number, then have the agent send the extension via DTMF.

What to do:

Configure transfer_to_number with the main destination in E.164 format only (e.g., +12125551234). Extensions aren’t supported in the number string. (elevenlabs.io)
Enable the Play keypad touch tone system tool and have the agent send the extension after the call connects (e.g., dtmf_tones like “W1234#”, where W adds a 1s pause). This tool works with Twilio and supports digits 0–9, *, #, and pauses w/W. (elevenlabs.io)
Be aware of transfer limits: using the native Twilio integration, transfers are limited to numbers hosted on Twilio. To transfer to external PSTN numbers or SIP URIs (and to use SIP REFER), use SIP trunking instead of the native Twilio integration (e.g., Twilio Elastic SIP) or host the destination on Twilio. (elevenlabs.io)

If you share the destination and extension pattern, I can suggest a precise DTMF sequence. (elevenlabs.io)

Sources:
Transfer to human | ElevenLabs Documentation
Play keypad touch tone | ElevenLabs Documentation
Transfer to human | ElevenLabs Documentation
Play keypad touch tone | ElevenLabs Documentation

covert socket Sep 21, 2025, 1:06 AM

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the desitnation is a zoom phone

craggy spindleBOT Sep 21, 2025, 1:06 AM

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AI-generated Answer for tailwind8960

Short answer: you can reach a Zoom Phone, but not via the native Twilio integration unless the destination number is itself hosted on Twilio. To transfer to an external carrier (e.g., Zoom Phone DID), use SIP trunking.

What to do:

If you’re on native Twilio telephony: transfers are limited to numbers hosted on Twilio. Zoom Phone DIDs (hosted by Zoom) won’t work with transfer_to_number in this mode. ElevenLabs recommends using Twilio Elastic SIP Trunking with our SIP trunking support instead of the native integration when you need external transfers. (elevenlabs.io)
Use SIP trunking with ElevenLabs: once your number is connected via SIP trunking, transfer_to_number can call external destinations (including a Zoom Phone DID). (elevenlabs.io)
If the Zoom destination requires an extension: dial the main Zoom number with transfer_to_number, then have the agent send the extension using the Play keypad touch tone tool (DTMF). You can include pauses with w (0.5s) or W (1s), e.g., “ww1234#”. (elevenlabs.io)
Optional (SIP-only): if Zoom provides a SIP URI and your trunk permits SIP REFER, you can configure transfer_to_number to use a SIP URI and SIP REFER. (elevenlabs.io)

References

Transfer to Human (numbers you can transfer to; Twilio vs external) (elevenlabs.io)
SIP trunking setup and capabilities (elevenlabs.io)
System tools: Play keypad touch tone (DTMF with pauses) (elevenlabs.io)
Transfer to Human (phone number or SIP URI; SIP REFER) (elevenlabs.io)

covert socket Sep 21, 2025, 1:22 AM

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can i do this: With conference transfer, dial extension BEFORE transferring:

Call the number
Send DTMF "WW5"
THEN transfer (agent leaves but extension is already dialed)

craggy spindleBOT Sep 21, 2025, 1:22 AM

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AI-generated Answer for tailwind8960

Short answer: You can send DTMF like “WW5” during a call, but the docs don’t guarantee a built-in “dial digits first, then transfer” sequencing.

What’s documented

DTMF: Agents can play keypad tones during phone calls using the play_keypad_touch_tone system tool. Valid characters include 0–9, *, #, plus pauses w = 0.5s and W = 1.0s (so “WW5” is valid). This tool only works during active Twilio or SIP trunking calls. (elevenlabs.io)
Conference transfer behavior: The default transfer_to_number mode “calls the destination and adds the participant to a conference room, then removes the AI agent so only the caller and transferred participant remain.” The documentation does not expose a parameter to delay the agent’s removal or otherwise guarantee that you can inject DTMF before the agent exits the bridge. (elevenlabs.io)

Important limitation for your setup (Twilio → Zoom Phone)

With the native Twilio integration, transfers are limited: “Twilio phone numbers currently can only transfer to phone numbers hosted on Twilio.” To transfer to external destinations (e.g., Zoom Phone), use SIP trunking (or Twilio Elastic SIP trunking via SIP) instead. (elevenlabs.io)
If you use SIP, you can choose SIP REFER transfers (only available over SIP) and, per docs, only SIP REFER supports transferring to a SIP URI. (elevenlabs.io)

Bottom line

You can have the agent send DTMF like “WW5” during a call, but the docs don’t confirm a workflow where the agent dials digits and then explicitly leaves afterward under conference transfer. If you must reach Zoom Phone from a Twilio number, switch to SIP trunking for transfers. (elevenlabs.io)

If you want, I can point you to the exact tool configuration fields to enable play_keypad_touch_tone and set transfer rules. (elevenlabs.io)

covert socket Sep 21, 2025, 1:45 AM

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when i transfer_to_number it always says a message like "Please wiat while i diret your call" in a default voice which isdifferent from my agent's voice. can i transfer silently without this being played to the cqllr when this tool is called?

craggy spindleBOT Sep 21, 2025, 1:45 AM

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AI-generated Answer for tailwind8960

Short answer: Yes, but only when you’re using the Twilio native integration. ElevenLabs added a configuration flag to Transfer to Human that lets you suppress the “please wait…” announcement.

What to do

Twilio native numbers: Set enable_client_message to false in the Transfer to Human tool configuration for your agent. This performs a silent (cold) transfer so nothing is played to the caller before the handoff. This parameter was added on June 8, 2025. See the changelog note and “Updated Endpoints → Transfer to Human.” (elevenlabs.io)
Otherwise (e.g., SIP trunking): The Transfer to Human tool still documents client_message as required (i.e., it will read a message to the caller). There’s no documented option to make it silent in this path. (elevenlabs.io)

Tip: If you do want something spoken (but not the default phrase), pass your own client_message to control exactly what the caller hears during transfer. (elevenlabs.io)

If you need help enabling the silent option on your account, reach out to ElevenLabs Support. (help.elevenlabs.io)

Sources:
June 8, 2025 | ElevenLabs Documentation
Transfer to human | ElevenLabs Documentation
Transfer to human | ElevenLabs Documentation
How can I contact support? – ElevenLabs

covert socket Sep 21, 2025, 2:05 AM

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i ahve done this and still it plays the message? wilio native numbers: Set enable_client_message to false in the Transfer to Human tool configuration for your agent. This performs a silent (cold) transfer so nothing is played to the caller before the handoff.

craggy spindleBOT Sep 21, 2025, 2:05 AM

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AI-generated Answer for tailwind8960

Short answer: Yes—on Twilio native numbers, setting enable_client_message to false in the Transfer to Human tool is the documented way to perform a silent (cold) transfer. This capability and parameter were added on June 8, 2025. (elevenlabs.io)

If you still hear a message after disabling it, here’s what the docs confirm and what to double‑check:

Supported scope: Silent transfer is documented specifically for the Twilio native integration. Ensure the call is using the Twilio native integration (not SIP trunking) and that your transfer type is the standard “conference” transfer used with Twilio native numbers. (elevenlabs.io)
Configuration: The Transfer to Human tool remains the mechanism for call handoff; its function schema still includes a client_message field, but the June 8, 2025 update added the enable_client_message flag in agent configuration to control whether anything is actually played to the caller. Make sure your latest agent configuration includes enable_client_message: false and has been redeployed. (elevenlabs.io)

The public docs don’t list any additional causes for a message playing after enable_client_message is disabled. If the behavior persists, it’s likely an implementation issue rather than expected behavior per docs—please share the affected call ID and agent ID with support. (elevenlabs.io)

Sources:
June 8, 2025 | ElevenLabs Documentation
June 8, 2025 | ElevenLabs Documentation
Transfer to human | ElevenLabs Documentation
Transfer to human | ElevenLabs Documentation

covert socket Sep 21, 2025, 2:16 AM

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can you telle me how to reach support?

#can i add a number with an extension to the transfer_to_number tool in conversational ai agent?