---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/13236#article
headline: "13236: Dial->Conference: Invalid Conference Sid"
url: https://www.twilio.com/docs/api/errors/13236
inLanguage: en
dateModified: 2026-06-08T11:38:30.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 13236: Dial->Conference: Invalid Conference Sid

Log Level: WARNING

## Description

This warning occurs when you try to connect to a conference by `ConferenceSid`, but the SID does not identify an existing conference or the conference has already been completed. Conference SIDs use the `CF` prefix, and a `ConferenceSid` must refer to an active conference.

### Possible causes

* The `ConferenceSid` is mistyped, truncated, or otherwise invalid.
* The `ConferenceSid` does not belong to a conference in your account.
* The `ConferenceSid` refers to a conference that has already ended and is now `completed`.
* Your application reused a stale `ConferenceSid` from an earlier call flow instead of the current active conference.

### Possible solutions

* Verify that you are passing the correct `ConferenceSid` for the conference you want to join. A valid conference SID starts with `CF`.
* Check the conference status before you reuse a stored SID. If the conference has been completed, create or reference a new active conference instead.
* If you want Twilio to create a conference when one does not already exist, use a named conference with `<Conference>` or use `FriendlyName` when creating a participant.
* Update your application logic to store the current active conference identifier and avoid reusing old conference SIDs after the conference ends.

#### Additional resources

* [TwiML Voice: `<Conference>`](/docs/voice/twiml/conference)
* [Conferences resource](/docs/voice/api/conference-resource)
* [Conference Participants subresource](/docs/voice/api/conference-participant-resource)