Whenever I add an extensions to my transfer calls it doesn't work. I'm working with a large property management company. I can transfer call whenever it's a person cell but whenever there is an extension included it doesn't work. https://cdn.discordapp.com/attachments/1436123276547067915/1436123276878544946/Screenshot_2025-11-06_at_5.39.48_PM.png?ex=690e7587&is=690d2407&hm=a47095c8adc7426d232522b398b8bcf771072e8f33a2412a8188286cc5d77e9d&

I can help you sort this out, this usually happens when the PBX or SIP provider doesn’t recognize how the extension is being passed during the transfer. I’ve handled similar VAPI setups where internal transfers failed due to missing headers or dial format issues. Could you share which phone system or provider you’re using so I can guide you on the right transfer format or SIP setup? @Remy

Hi highergroundnomad, To implement call transfers using Vapi, there are two primary methods: dynamic call transfers and assistant-based warm transfers. Here's a brief guide on both: 1. Dynamic Call Transfers: - No Webhook: The assistant supplies the destination directly using a parameter like

phoneNumber

. This requires a

dynamicTransfer

tool with an empty

destinations

array. No webhook is sent. - With Webhook: The server decides the destination by responding to a

transfer-destination-request

webhook. Your tool should have an empty

destinations

array, and you can utilize context parameters like

reason

or

urgency

. For setup, refer to the [Dynamic Call Transfers documentation](https://docs.vapi.ai/calls/call-dynamic-transfers). 2. Assistant-Based Warm Transfers: - Use a dedicated transfer assistant to manage the process. This involves the assistant making transfer decisions based on the conversation context. Configuration includes setting up transfer tools and specifying behaviors with prompts. Details on this implementation can be found in the [Assistant-Based Warm Transfer guide](https://docs.vapi.ai/calls/assistant-based-warm-transfer). For both cases, you can configure tools via the Vapi dashboard or API to route calls intelligently based on various conditions. Adjusting webhook and prompt settings allows for flexible handling and ensures secure and efficient call transfers.

Hi @Remy please watch out for @User . He says he knows the answer to your problem and he can help. But he will ask for money upfront. I made the mistake of doing so and never heard back from him. I already reported him in the # report-scam channel. But I wanted you to be aware of him. Cheers!