DLT Registration for SMS in India: A Step-by-Step Guide

Why DLT exists

TRAI (the Telecom Regulatory Authority of India) mandates that every commercial SMS sent in India be traceable back to a registered, verified sender. The mechanism for that is DLT, a distributed-ledger registry run by the telecom operators, where businesses register their identity, their sender headers, and the exact content templates they intend to send. Operators must ensure commercial SMS only goes out under registered headers and templates, so a message that doesn't match one is blocked before it reaches the recipient.

This isn't optional or a "nice to have" — it's the mechanism that makes commercial SMS delivery possible in India at all. Any SMS gateway provider that tells you otherwise either handles DLT registration on your behalf without saying so, or the messages simply won't deliver reliably.

The three things you register

• Entity registration: your business registers as a sender on an operator's DLT platform, submitting the business identity documents that platform asks for, and receives a unique Entity ID
• Sender ID / header registration: the alphanumeric header that appears as the sender (e.g. "MSGIFY") is registered against your Entity ID for a message category (promotional, transactional, service or government). Since 2025, recipients see a suffix on the header (-P, -S, -T or -G) showing which category the message belongs to
• Template registration: every distinct message template you plan to send is submitted with its fixed text and variable portions identified (most DLT portals mark variables as {#var#}), and is matched at send time. A message that doesn't match an approved template is rejected even when the sender ID is valid

The order matters

Entity registration has to be approved before sender headers can be registered, and templates are registered against an approved header. Each step needs operator approval, and turnaround varies by operator. If SMS is on a launch-critical path, start registration well before launch day.

For the portal-by-portal steps, header naming rules and fees, see DLT header registration on Jio, Airtel, Vi and BSNL. Messagify's SMS gateway with DLT onboarding guides you through entity, header and template registration and maps your template IDs in the integration.

Promotional vs. transactional: why the category matters

The category determines who a message can reach. Promotional messages must include an opt-out and are delivered only to people who haven't blocked that category in their preferences (which can include time bands and days), unless you hold their explicit digital consent. Transactional messages, such as an OTP or a confirmation sent in response to a customer's own transaction, and service messages to your existing customers about a product they use are not treated as unsolicited commercial communication, so DND preferences don't block them. Mixing promotional content into a transactional or service message makes the whole message promotional, and misusing headers or templates can get them suspended.

Frequently Asked Questions

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