---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/48002#article
headline: "48002: Callback URL is invalid"
url: https://www.twilio.com/docs/api/errors/48002
inLanguage: en
dateModified: 2026-06-09T11:00:42.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 48002: Callback URL is invalid

Log Type: TWILIO

Log Level: ERROR

## Description

Twilio could not process the request because the callback URL you provided is not valid. This error occurs when a request includes a malformed URL, an unsupported scheme, or a callback value that cannot be used to deliver webhooks.

### Possible causes

* The callback URL is malformed
* The URL uses an unsupported or invalid scheme
* The URL contains invalid characters or formatting errors
* The callback URL value is empty, truncated, or incomplete
* The request parameter that contains the callback URL was populated with the wrong value

### Possible solutions

* Confirm that the callback URL is a complete, properly formatted URL
* Use `https://` for production webhook endpoints
* Check for common formatting issues such as missing hostname, missing scheme, extra spaces, or invalid characters
* Verify that you passed the callback URL in the correct request parameter for the API resource you are using
* If you generate the URL in code, log the final value before sending the request to Twilio and confirm that it matches the endpoint you expect
* Test the webhook endpoint with a public, reachable URL and confirm your application returns a valid HTTP response