21901: DltTemplateId is invalid

The DltTemplateId value in your request is not valid. This error occurs when you send an invalid Distributed Ledger Technology template identifier for messaging in India, or when the value does not match the format Twilio expects for a registered DLT template.

• The DltTemplateId value is missing required characters or contains an invalid format.
• The DltTemplateId value is longer than the supported limit.
• The DltTemplateId value does not match the template ID registered with your sender on the applicable DLT platform.
• You submitted a DltTemplateId for traffic that does not use an approved India DLT template configuration.
• Your application passed the wrong parameter value, such as a template name or internal identifier instead of the DLT template ID.

• Verify that you are sending the correct DltTemplateId value for your registered India messaging template.
• Review your application logic to confirm that the DltTemplateId parameter is populated with the expected template ID and not another internal reference.
• Remove extra characters, whitespace, or formatting issues from the DltTemplateId value before sending the request.
• Confirm that the template ID you use matches the sender, template, and use case approved in your DLT registration.
• Review your India compliance and messaging configuration before resubmitting the message.

• Programmable Messaging documentation
• Send Messages with the Twilio API
• India messaging guidelines