TRAI DLT explained: entity, header, template and consent

If you have tried to send bulk SMS in India, you have met the letters DLT. Distributed Ledger Technology is the system operators use, under TRAI's Telecom Commercial Communications Customer Preference Regulations (TCCCPR) of 2018, to make sure commercial SMS comes from a known sender, uses an approved message format and respects the recipient's preferences.

The process looks complicated at first, but it comes down to four registrations.

1. Principal Entity (your business)

You register your business once on any operator's DLT portal (Jio, Airtel, Vi, BSNL and others run them). You submit identity documents such as PAN and GST details and receive a Principal Entity ID. Registration on one portal is shared across operators.

2. Header (sender ID)

The header is the short name that appears as the sender, for example SGRECH. Each header is linked to your entity and to a type of communication. Choose something recognisable: customers trust a header that matches your brand.

3. Content templates

Every message you send must match a registered content template. Fixed text stays fixed, and the parts that change per customer are variables. Since TRAI's direction of 18 November 2025, operators must make sure every variable is pre-tagged with its type, such as #url# for links or #number# for numbers, and check it against whitelisted values. We cover that rule in detail in a separate article.

4. Consent templates (for promotional messages)

Promotional messages to people who have not opted out of promotions need recorded consent. DLT portals let you register a consent template that describes how you collected it.

Transactional, service and promotional

Templates are registered under a category:

• Transactional: for example OTPs from banks.
• Service: updates customers expect, like order and appointment messages.
• Promotional: offers and marketing, which are blocked for numbers registered on the Do Not Disturb list for that category.

Common mistakes

• Registering a template with fixed text, then changing the wording when sending. Even small edits cause rejection.
• Using too many variables. A template that is "all variable" is likely to be rejected.
• Putting links in a variable that is not tagged and whitelisted, which is now checked by operators.

How SG Reach helps

In SG Reach each SMS gateway stores your sender ID and DLT entity ID, and each SMS template stores its DLT template ID. Campaigns send the variables in the order your template expects. Gateways such as MSG91 and Fast2SMS that only accept DLT templates are enforced at send time, so you find mistakes before the campaign goes out.