Referring to call ID: 58915be9-a050-4166-b73c-7b78199fb60d. I have simulated a call to get Voice AI to transfer the call to human agent. I have set a transfer number but its not doing it. Assistant ID: efb4517c-92ba-47a9-bfa2-37409b69bc3f

Hi there! 👋 I see you're having trouble with the call transfer feature. Let me help you troubleshoot this issue. Based on the documentation, here are some steps you can try: 1. Check SIP REFER Compatibility Make sure your SIP system is configured to handle SIP REFER messages, as Vapi uses these for call transfers. [This has been a common issue for other users](https://discord.com/channels/1211482211119796234/1211483291191083018/1333747605628391434). 2. Review Your Transfer Configuration Verify that the

transferCall

function is properly configured with the correct destination number in E.164 format. For example:

json
   {
     "function": {
       "name": "transferCall",
       "parameters": {
         "destination": "+1234567890"
       }
     }
   }

3. Check Call Logs Examine the call logs for your specific call ID to see if there are any error messages indicating why the transfer failed. [This can provide valuable insights](https://discord.com/channels/1211482211119796234/1211483291191083018/1340813822193041499). 4. Network Settings Verify network configurations for any latency or restrictions that might affect call transfers. [Network issues can sometimes prevent successful transfers](https://discord.com/channels/1211482211119796234/1211483291191083018/1332133296347549797). 5. Try Different Transfer Mode Ensure you're using the correct transfer mode - either blind transfer (default) or warm transfer. [Different modes may work better for your use case](https://docs.vapi.ai/call-forwarding). If you're still experiencing issues, it could be related to one of the known issues with call transfers, such as inconsistent transfers, silent failures, or configuration problems with external systems. Let me know if any of these steps help or if you need more specific guidance! Sources:

🔵 23:09:27:728 Transferring Twilio Call...TwiML:<Response><Dial><Number>+614500xxxx</Number></Dial></Response> @ivy from our side call was transfered can you share your twilio logs for this twilio call SID

CA0a74de4368ff33becba2c5f2c8c52161

Thanks @Shubham Bajaj it looks like that number been blocklisted by Twilio. How do I unblock that number? https://cdn.discordapp.com/attachments/1348607733812695101/1349191594074574888/image.png?ex=67d23416&is=67d0e296&hm=c9e7aa5a3dece8113853cbddfc3086eb0bf5e6178c48ba40f8de0214fb5aaf21& https://cdn.discordapp.com/attachments/1348607733812695101/1349191594498326601/image.png?ex=67d23416&is=67d0e296&hm=a54ec17fcda9edd151a02705f5dca7e1f012a68b76e8d8e8ddc5a4411f05b599&

Hey Ivy, you can submit a request to Twilio support if you feel that number has been unjustly blacklisted. Unfortunately it isn't something we have control over.

Thanks Mason I have managed to get Twilio to whitelist it

Glad to hear! Happy building.