WaZappy
Himanshu Chawla
If your OTPs or order alerts suddenly stop delivering, DLT is usually the reason. Since TRAI made Distributed Ledger Technology registration mandatory for commercial SMS, every message must match a registered sender, header and template. Here is the checklist we follow — Infrared Techno is itself a DLT-registered principal entity, so this is based on doing it, not just reading about it.
Key takeaways
- Register your business as a Principal Entity (PE) on one operator's DLT portal; it works across operators.
- Register headers (sender IDs) and every message template, including variables.
- Messages that do not match an approved template exactly are blocked.
Step 1: Register as a Principal Entity
Choose any operator's DLT portal (Jio, Airtel, Vodafone Idea, BSNL and others). You will need your business PAN, GST certificate or other registration proof, an authorisation letter on letterhead, and the authorised person's ID. Approval typically comes after document verification and a registration fee.
Step 2: Register headers (sender IDs)
Headers are the six-character sender names customers see, such as INFRAT. Transactional and service headers are alphabetic; promotional headers are numeric. Choose names that clearly relate to your brand — unrelated headers are often rejected.
Step 3: Register content templates
Every message you send must be registered as a template with variables marked as {#var#}. For example:
Dear {#var#}, your order {#var#} has been dispatched and will reach you by {#var#}. - BrandTemplates are categorised as transactional, service implicit, service explicit or promotional. Picking the wrong category is the most common reason for rejection.
Step 4: Consent and customer preferences
Promotional messages must respect DND preferences and permitted sending hours. Service-explicit messages need recorded consent. Keep a record of how each customer opted in.
Step 5: Connect your SMS provider
Share your PE ID, header and template IDs with your SMS gateway and pass the template ID with each API request where required. Then test every template end to end before going live.
Checklist before you go live
- PE ID approved and shared with the gateway
- Headers approved for each use case
- All templates approved and mapped in your code
- Variables tested with real values (length limits!)
- Delivery reports logged in your system
- WhatsApp as a fallback or primary channel for rich messages
Frequently asked questions
Is DLT needed for OTP SMS?
Yes. OTP and other transactional messages also require DLT-registered headers and templates.
How long does DLT registration take?
It varies by operator and how complete your documents are. Keep documents ready to avoid back-and-forth.
