Hi, I’m reaching out regarding a critical issue that’s now affecting over 60 of our clients. Until a few weeks ago, our outbound calls via the /call API worked reliably. But recently, nearly all outbound calls are now failing with the status "Customer Did Not Answer". Even test calls to our own internal numbers are not ringing, despite the API returning a 200 Success. Here’s an example error that A Vapi team member sent us that they saw in their internal logs for the failed calls: 🔵 11:56:18:082 Call e65b59a5-bf02-451b-8a14-5cdc08b37f2d - Waited 300s But Transport Never Connected. We escalated this to Twilio support and provided call timestamps and phone numbers. Their response was clear: The calls never reached Twilio. They do not exist in their logs. This confirms the issue is occurring before the handoff to Twilio, likely on Vapi’s side. We urgently need your help to: 1. Diagnose what’s preventing the calls from being handed off to Twilio 2. Verify what Vapi is returning internally when these calls are initiated 3. Restore reliable outbound calling, as this is impacting real-time lead response for all clients Let us know if you need further logs or test cases—we’re happy to provide them. Thanks in advance for your quick support. This is business-critical.

Actionable Next Step: Please review any recent changes to your SIP trunk or webhook configurations, as these are common causes for outbound call transport failures. Then, collect a sample of affected call IDs and timestamps, and email them to [support@vapi.ai](support@vapi.ai) for direct escalation. This will help Vapi's technical team investigate backend logs and expedite resolution for your business-critical issue. If you need a template for your support request, let me know! Sources: - [Vapi outbound call not triggering (Discord)](https://discord.com/channels/1211482211119796234/1341449578100031488) - [Vapi support options](https://docs.vapi.ai/support)

@Vapi Support Bot We've simply changed the inbound webhook in Twilio to a custom function, but this should not be impacting outbound calls, right?

Thank you for clarifying the recent change. To help diagnose the issue: Did your custom inbound webhook function in Twilio make any changes to SIP trunk settings, phone number configurations, or authentication details that might also affect outbound call routing or permissions? Even small changes in these areas can sometimes impact outbound call transport. If possible, please confirm whether any such settings were modified, as this will help narrow down the root cause. Source: - [Vapi support options](https://docs.vapi.ai/support)

Could you please provide your org id and the phone number id? We would like to look at the configuration of this integration