# 90009: The message SID already exists.

Log Type: APPLICATION

Log Level: ERROR

## Description

This error means the request to create a Message resource conflicts with an existing message SID. Twilio identifies each resource with a unique SID, and this error page lists a duplicate message SID as the cause when creating a new message.

### Possible causes

* A message with the same SID already exists, so the new message request conflicts with an existing resource.
* Your integration reused a message identifier instead of creating a unique value for the new message. Twilio uses unique SIDs to identify resources.

### Possible solutions

* Generate a new, unique message SID before you retry the request.
* Make sure your application does not reuse the same identifier when creating messages.
* If you need to inspect an existing message, fetch it with the Messages resource using its SID.

#### Additional resources

* [Messages resource](/docs/messaging/api/message-resource)
* [What is a String Identifier (SID)?](/docs/glossary/what-is-a-sid)