​ To learn more, see the sources I considered: [[1] Dynamic Variables](https://docs.retellai.com/build/dynamic-variables) [[2] Call Transfer Node](https://docs.retellai.com/build/conversation-flow/call-transfer-node) [[3] Create Web Call](https://docs.retellai.com/api-references/create-web-call) [[4] Call transfer extension number not working in call transfer node](https://discord.com/channels/1186424376300679209/1425942962810130452) ​

### Answer Dynamic variables can be used in the Transfer To Target field of the Call Transfer Node. [(1) ]() [(2) ]() To set up a dynamic variable for the transfer number with an extension: 1. Set the transfer number to a dynamic variable using the

{{variable_name}}

syntax in the Transfer To Target field 2. Set the transfer number extension in the separate extension field - extensions must be 0-9, '*', '#' (e.g., 123#) [(2) ]() 3. Pass the dynamic variable value when creating the call using the

retell_llm_dynamic_variables

field [(3) ]() For example, if you want to transfer to a number stored in a dynamic variable, you would: - In the Transfer To Target field, enter:

{{transfer_phone_number}}

- In the extension field, enter the extension directly (e.g.,

1234#

) - When creating the call, pass the phone number value in

retell_llm_dynamic_variables

Note: Based on community discussions, there have been reported issues with extensions not being included in transfer calls during actual calls (though they appear correctly in testing) . [(4) ]() If you encounter issues, you may want to try selecting "Keep raw input" in the transfer settings.

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

### Answer For Dynamic Routing in the Call Transfer Node, the extension field is separate from the transfer number field. [(1) ]() When using Dynamic Routing, you should structure your prompt to output the phone number in the transfer number field, and then configure the extension separately in the dedicated extension field. The extension field accepts values that must be 0-9, '*', '#' (e.g., 123#) . For your scenario with conditional routing based on location status, you would: 1. In the Dynamic Routing text field, write a prompt that instructs the agent to determine which number to transfer to based on the condition 2. The agent will output the phone number (e.g., +3531357890) 3. Configure the extension field separately with the appropriate extension value However, based on the available documentation, the extension field appears to be a single static value per Call Transfer Node, not dynamically determined by the agent's routing logic. If you need different extensions based on different conditions (EXT 1 vs EXT 2) , you may need to create separate Call Transfer Nodes for each scenario, with each node having its own extension configured, and use conditional edges to route to the appropriate transfer node based on your location status check.

​ 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.