Transfer even if hit voicemail

Currently when it transfers a call it is using SIP Refer but if the other side does not pick up or it goes to voicemail it brings the call back to the AI to say they were not available. Is there a way to fully send the call over regardless of if the other side picks up to allow the caller to leave them a voicemail?

This is the result I get when it comes back to the AI: {“status”:“Transfer call cannot be completed, the other side did not pick up.. Please inform the customer that the transfer did not go through and offer to try again or assist them directly.”}

Hey @hello6

Could you plz share your Agent ID with the Relevent Call IDs?

Thank you

@Shah-Fazal call_1d8f389ae076257453afaf6b43a
call_1d1f6b4895719a3f8e4ca8fbf97
call_ba1a02762eec4e2d56e2640191f

agent_9ff7d4857f9729a8391884204a

Thanks!

I figured it out. I needed to extend the amount of time to ring the transfer (from 30s to 60s). Thanks

@Shah-Fazal - sorry I just realized it had nothing to do with the ringing time. Although it shows the call came back to the AI and the AI says sorry they were not available… what is actually happening is the caller was connected to the voicemail and does not even hear that part of the AI. Why does the AI still think it is connected to the caller even though the call is no longer in retell? How can we fix this? Because it is confusing the client when they see the transcript.

@hello6 Ok I’ll check with the team on this.

Hey @hello6 you need to use sip invite.

But the transfer works correctly right now that’s what I’m saying. For some reason Retell still thinks the caller is on the line and starts speaking to them assuming the transfer failed but in reality the caller has already been transferred.

Hey @hello6 can you share the new call id?

Hi it’s all the same as the ones I sent earlier in the thread.

Hey @hello6 It seems like there are two different issues compared to what you initially reported.

first you mentioned that the issue occurs when the other side does not pick up, which is what the call logs show. However, now saying that the caller was transferred successfully.

Yes because I tested it myself. If you just look at the transcript and call log, you would assume the person returned back to the AI as it shows it was unsuccessful. But in reality, the caller already is on the other line leaving a voicemail and does not even hear the Retell AI agent speaking. So the transfer is working fine. I would like you to look into why retell agent starts talking again and thinks the caller is still on the line when they aren’t anymore. Does that make sense?

Hey @hello6 seen the same behavior flagged a few times, seems is because you are still using sip refer. Will ask product team why this is.

@Shah-Fazal did you hear back?

Hey! Andrew here from Call Sandwich — we’re Elite Certified Partners with Retell since June 2024 and work closely with the Retell team on the telephony side. I took a look at the specific calls you shared and I think I know exactly what’s happening here.

Your transfers are actually succeeding — Retell just doesn’t know it yet

What we’re seeing in the call captures is that when you transfer to certain numbers, the other side takes longer than 30 seconds to pick up (this is common with mobile numbers — they just ring slower). Retell hits its transfer timeout at 30 s, assumes nobody answered, and hands the call back to your agent, which then goes into your Take Message node. But here’s the thing — the transfer did go through. The other side picked up shortly after that 30 second mark. So your caller ends up leaving a voicemail with the transferee while your AI is also talking to them from the Retell side. That’s the weird double-experience you’ve been noticing.

What to do

Go into your transfer call tool settings and increase the timeout to somewhere between 60–90 seconds. That’s the amount of time Retell will wait for the other side to answer before giving up. Based on what we saw in your calls, a successful answer was coming in right around the 33–34 second mark — so the 30 s default is just barely missing it. Bumping it to 60–90 s gives you a proper safety margin.

Let me know if you need help finding where to update that timeout setting and I’ll walk you through it!

Hey @hello6 I have pinged the team again.

Hey @hello6 There are no updates on this. We are still checking internally

Thanks! In the meantime, I had another question regarding data-white-label option in the chat widget. How can I obtain the white label token? I have been a retell partner for a while now. Thanks!