---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/21209#article
headline: "21209: Invalid Method"
url: https://www.twilio.com/docs/api/errors/21209
inLanguage: en
dateModified: 2025-12-18T21:40:49.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 21209: Invalid Method

Log Level: ERROR

## Description

You attempted to initiate an outbound phone call, but you sent a Method parameter that was invalid. Method specifies what HTTP method Twilio should use in contacting your web server. Possible values are `GET` and `POST`.