90009: The message SID already exists.

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.

• 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.

• 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.

• Messages resource
• What is a String Identifier (SID)?