---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/21901#article
headline: "21901: DltTemplateId is invalid"
url: https://www.twilio.com/docs/api/errors/21901
inLanguage: en
dateModified: 2026-06-09T11:00:42.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 21901: DltTemplateId is invalid

Log Type: APPLICATION

Log Level: ERROR

## Description

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.

### Possible causes

* 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.

### Possible solutions

* 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.

#### Additional resources

* [Programmable Messaging documentation](/docs/messaging)
* [Send Messages with the Twilio API](/docs/messaging/tutorials/how-to-send-sms-messages)
* [India messaging guidelines](https://help.twilio.com/articles/360037746094-SMS-Guidelines-for-India)