How Exotel is Making it Easy for Businesses to Comply with DLT Regulations

June 16, 2021

The Telecom Regulatory Authority of India (TRAI) is constantly looking for ways to improve end-user experience. Their goal is to eliminate spam and fraudulent commercial communication and they keep introducing various regulations periodically to safeguard end users. However, their latest regulation passed in 2018 has made it extremely difficult for businesses to send SMS communication. This blog post will cover what the new regulation means, how it impacts business and how Exotel has made it easy for our customers to comply with this regulation.

Table of Contents

What is DLT?

DLT stands for distributed ledger technology and is the core essence of this new platform built to prevent SMS spam. DLT is the same technology used by cryptocurrencies in the form of blockchain.

By definition, DLT is a digital system for recording the transaction of assets. It records the transactions and their details in multiple places at the same time. Unlike traditional databases, distributed ledgers have no central data store or administration functionality.

In the case of SMS, different operators in India (Airtel, Jio, Vodafone-Idea, BSNL, Tata etc.) are storing the SMS data related to business entities such as Sender ID, Templates etc. This data is not owned by a single authority but shared across operators.

How does this regulation prevent spam/fraud?

Earlier, without DLT, it was easier to commit two kinds of fraud:

  • Misuse of another company’s sender ID: Before, if any false actor got access to a telemarketer’s SMS API, they could misuse the Sender ID and send SMS posing as another business. Financial scams posing as PayTM or banks were very common. Now, with DLT, every SMS is validated by operators and matched against the Businesses Entity ID.
  • Fraudulent SMS content: Previously, anything could be sent via an SMS without any checks for fraudulent links, gambling etc. Now, the SMS content needs to be approved by DLT platforms. This process is maintained by operators and pertains to certain guidelines. Also, the content of each SMS now needs to be validated with the Template ID.

That’s not all – DLT has more things in store in the upcoming years. In the future, DLT will be mandating businesses to upload the consent of a user to the DLT platform. After this mandate is in place, only users who have explicitly consented to receiving SMSes will get an SMS. The same regulations will also apply to calls. This is expected to reduce spam by a great deal.

How are the DLT regulations impacting Businesses?

With such stringent regulations and steps in place, it has become difficult for businesses to register and comply with TRAI’s regulations.

They have to

  • Register their business on DLT
  • Register all Sender IDs and templates they use. Approvals can take long at times.
  • Provide the DLT Entity ID and the Template ID to their SMS providers before sending SMSes.

All of these steps are prone to manual errors and add a massive overhead for businesses.

The impact was so huge that even government agencies like Aadhar’s OTP were failing on the first rollout of the DLT Template mandate. TRAI had to revert this regulation as the majority of SMS traffic in India was failing. They’ve enabled this now only after giving ample time to businesses to set things up.

DLT Registration process made easy with Exotel

Exotel has taken the following steps to make sure that complying with these new regulations is easy for our customers:

1. If you’re sending SMSes via Exotel’s SMS API, here’s what you need to do to comply with the regulations:

  • Pass on your DLT identifiers – Entity ID and Template ID – to our API and Exotel will get your SMS delivered to Operators. You can find all the steps required here
  • No need to register / add any templates on the Exotel dashboard- just pass it via your API request. You can do this using SmsType parameter as ‘transactional’ or ‘promotional’

Refer to our documentation here for more details.

Sample Request

curl -X POST https://<your_api_key>:<your_api_token><subdomain>/v1/Accounts/<your_sid>/Sms/send \
-d "From=EXOXXX" \
-d "To=XXXXX30240" \
-d "Body=Hello World!"
-d "DltEntityId=XXXXXXXXX"
-d "DltTemplateId=XXXXXXX"
-d "SmsType=transactional"

2. I don’t want to make API changes

–  If you don’t want to make API changes, we have a solution for you – 

  • Configure DLT Entity ID on Exotel’s Dashboard (Settings)
  • Add all Templates and DLT details on Exotel’s Dashboard as registered on DLT portal or just email the downloaded CSV from DLT portal to and we’d automatically add it to your account

  • We also accept templates as per DLT format i.e. {#var#} can be used as a placeholder for variable content.

3. In-depth SMS failure reports

–  To help you identify DLT errors and correct them, we have added specific error codes for DLT failures in our SMS reports. Here is the list of codes and errors Exotel can identify:

  • SENDER_BLOCKED_BY_DLT – This means your Sender ID is not registered on DLT.
  • ENTITY_BLOCKED_BY_DLT – This means your DLT Entity ID is either not registered on DLT or there’s a type.
  • TEMPLATE_BLOCKED_BY_DLT – This means your Template is either not registered on DLT or it’s not matching exactly. It could also mean your Template ID is incorrect or Sender ID (header) is not linked with the particular template.
  • FAILED_DLT_SCRUBBING_ERROR – This indicates any other error due to DLT at the operator end.

–  These error codes are provided to you in Exotel’s SMS Outbox, SMS Reports and via the GET SMS Details API.


Here are some of our knowledge base articles to help you further with any questions you may have:

For any queries on DLT, just reach out to your account manager or our support team ( and we’d be happy to help!



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