If you're sending commercial SMS messages in India, you need to comply with TRAI's Distributed Ledger Technology (DLT) regulations. No exceptions, no workarounds. Non-compliant messages simply don't get delivered — and repeated violations can result in your sender ID being blacklisted. (Once you're past DLT, WhatsApp is where the real engagement is, but you still need SMS for transactional flows.) This guide covers everything you need to know in 2026.
What Is DLT and Why Does It Exist
TRAI (Telecom Regulatory Authority of India) introduced DLT regulations to combat the spam epidemic in Indian telecommunications. Before DLT, businesses and spammers alike could blast millions of unsolicited SMS messages with zero accountability. DLT creates an auditable trail: every sender must register, every message template must be pre-approved, and every recipient must have given consent.
The system is built on blockchain technology (hence "Distributed Ledger"), with multiple DLT operators (Jio, Airtel, Vodafone-Idea, BSNL, MTNL) maintaining synchronized records of registered entities, templates, and consent.
Step 1: Principal Entity (PE) Registration
Your business must register as a Principal Entity on at least one DLT platform. You'll need your company's PAN card, GST certificate, Certificate of Incorporation, authorized signatory details, and a letter of authorization on company letterhead. Registration typically costs ₹5,000-10,000 and takes 3-7 business days for approval.
Step 2: Sender ID (Header) Registration
Your sender ID is the 6-character alphanumeric name that appears as the sender of your SMS (e.g., VIZIQO). You need to register each sender ID you plan to use. Categories include Promotional (P), Transactional (T), Service Implicit (SI), and Service Explicit (SE) — each with different delivery rules and time restrictions.
Promotional messages can only be sent between 9 AM and 9 PM. Transactional messages can be sent 24/7. Understanding these categories is crucial for campaign planning.
Step 3: Content Template Registration
Every SMS you send must match a pre-registered template. Templates include the fixed text and variable placeholders (marked with {#var#}). For example: "Dear {#var#}, your order {#var#} has been shipped and will arrive by {#var#}. Track at {#var#}" — this template allows you to fill in the customer name, order ID, delivery date, and tracking link.
Template approval takes 1-3 business days. Plan your campaigns in advance and submit templates early. Rejected templates can be resubmitted after modifications.
Step 4: Consent Management
For promotional messages, you must have explicit opt-in consent from recipients, recorded and stored for audit purposes. Consent records must include the source of consent, timestamp, and the specific categories of messages the user agreed to receive.
Transactional messages (order confirmations, OTPs, account alerts) don't require explicit marketing consent but must be directly related to a service the customer is using.
Common Mistakes That Block Delivery
Template mismatch is the number one issue — if your actual message doesn't match the registered template pattern, it gets blocked. Other common problems: sending promotional messages outside the 9 AM-9 PM window, using unregistered sender IDs, exceeding variable character limits defined in templates, and not scrubbing against the DND (Do Not Disturb) registry.
How VIZIQO Campaign Handles DLT
We built DLT compliance directly into VIZIQO Campaign's workflow. When you create an SMS campaign, the platform validates your message against registered templates before sending, blocks sends outside permitted time windows for promotional messages, manages consent records automatically, and handles DND registry scrubbing. You focus on your campaign content — we handle the compliance.