---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/21205#article
headline: "21205: Invalid URL"
url: https://www.twilio.com/docs/api/errors/21205
inLanguage: en
dateModified: 2026-03-11T20:01:16.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 21205: Invalid URL

Log Level: ERROR

## Description

You attempted to initiate an outbound phone call, but the URL you specified to handle the call was not a valid URL.

If you specified an Application Sid for your outbound phone call, the application must have a valid VoiceUrl or the call will fail.

### Possible solutions

Make sure you submit a fully qualified URL including:

* protocol (http:// or https://)
* hostname
* file path
* properly url-encoded query parameters

Twilio must be able to reach this URL over the public Internet.