Caller ID Not Showing Customer Number During Transfer
Description:
I’m trying to configure my VAPI workflow so that when an outbound call is transferred, the customer’s number appears as the Caller ID on the transferred leg.
Currently, my setup uses a Twilio number with Refer enabled, and the workflow performs outbound calls to customers before transferring them. I initially assumed I’d need to use sipverb: "refer" to preserve the Caller ID through the transfer, but with that configuration, the call just drops as soon as the transfer is attempted.
Goal:
When the workflow transfers a customer call, the receiving party should see the customer’s number as the Caller ID, not the agent’s or trunk number.
What I’ve Tried:
Setting caller_id in VAPI to {{customer.number}} – has no effect.
In Twilio Elastic SIP Trunk settings, under Caller ID for Transfer Target, I selected “Set Caller ID as Transferor.”
Verified that the Twilio number supports and has Refer enabled.
Issue:
Despite these configurations, the transfer either drops or continues showing the agent/trunk Caller ID instead of the customer’s number.
Question:
Is there a supported way within VAPI (or Twilio configuration) to make outbound transfer calls display the customer’s number as the Caller ID? If using SIP Refer isn’t the correct approach for this, what’s the recommended setup to achieve that Caller ID behavior?
I’m trying to configure my VAPI workflow so that when an outbound call is transferred, the customer’s number appears as the Caller ID on the transferred leg.
Currently, my setup uses a Twilio number with Refer enabled, and the workflow performs outbound calls to customers before transferring them. I initially assumed I’d need to use sipverb: "refer" to preserve the Caller ID through the transfer, but with that configuration, the call just drops as soon as the transfer is attempted.
Goal:
When the workflow transfers a customer call, the receiving party should see the customer’s number as the Caller ID, not the agent’s or trunk number.
What I’ve Tried:
Setting caller_id in VAPI to {{customer.number}} – has no effect.
In Twilio Elastic SIP Trunk settings, under Caller ID for Transfer Target, I selected “Set Caller ID as Transferor.”
Verified that the Twilio number supports and has Refer enabled.
Issue:
Despite these configurations, the transfer either drops or continues showing the agent/trunk Caller ID instead of the customer’s number.
Question:
Is there a supported way within VAPI (or Twilio configuration) to make outbound transfer calls display the customer’s number as the Caller ID? If using SIP Refer isn’t the correct approach for this, what’s the recommended setup to achieve that Caller ID behavior?
