### Answer --- Yes, you can use a SIP URI in the Call Transfer node. [(1) ]() [(2) ]() The transfer number can be set to either: - A number in e.164 format - A SIP URI in the format

sip:username@domain

(e.g.,

sip:user@retellai.com

) - A dynamic variable that gets substituted at runtime

​ To learn more, see the sources I considered: [[1] Transfer call](https://docs.retellai.com/build/single-multi-prompt/transfer-call) [[2] Call Transfer Node](https://docs.retellai.com/build/conversation-flow/call-transfer-node) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

Thanks for the feedback, glad I was helpful.

### Answer --- I don't have explicit documentation in the available sources that confirms whether SIP URIs can be used specifically in dynamic routing configurations. The sources do confirm that the

transfer_destination

field can be a phone number or a SIP URI (prefixed with

sip:

and may include

;transport=...

) , and that dynamic variables are supported for transfer numbers. [(1) ]() [(2) ]() However, the specific behavior of dynamic routing with SIP URIs isn't explicitly documented in the sources I have access to. Check out these potentially useful sources: - [Transfer call]() - [Call Transfer Node]() Would you like me to provide a general answer based on my knowledge, or would you prefer to reach out to Retell support for confirmation?

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

​ To learn more, see the sources I considered: [[1] Register Phone Call](https://docs.retellai.com/api-references/register-phone-call) [[2] Help on Twilio DID questions](https://retell.discourse.group/t/help-on-twilio-did-questions/24) ​

### Answer Based on the documentation, SIP URIs should work with dynamic routing since: 1. The Call Transfer Node accepts a transfer number as either a phone number in e.164 format or a SIP URI in the format

sip:username@domain

(e.g.,

sip:user@retellai.com

) . [(1) ]() 2. The transfer number can also be set to a dynamic variable that gets substituted at runtime. Since dynamic variables are supported for the transfer destination field, and that field accepts SIP URIs, you should be able to use a dynamic variable containing a SIP URI for dynamic routing. For example, you could: - Set the transfer destination to a dynamic variable like

{{transfer_target}}

- Update that variable at runtime with a SIP URI value (e.g.,

sip:user@yourdomain.com

) The key is ensuring your SIP URI follows the correct format:

sip:username@domain

. If you encounter issues, I'd recommend testing with a static SIP URI first to confirm connectivity, then switching to a dynamic variable approach.

​ To learn more, see the sources I considered: [[1] Call Transfer Node](https://docs.retellai.com/build/conversation-flow/call-transfer-node) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.