---
page_type: error
code: 32503
message: "32503: Voice Conversation: Callback event response error."
level: WARNING
product: Programmable Voice
---

## Description

Request to status callback URL received a response error from the customer-side server.

### Possible Causes

- This error indicates that Twilio was able to reach the customer-provided URL, however, received an error from the customer-side callback endpoint.
- The URL provided was likely valid, but Twilio might be receiving an error from the customer-side service.

### Possible Solutions

- Make sure you have a web server up and running that serves that URL with the configured method in TwiML, e.g. POST.