What is DLT? The Full Form and Why It Exists
DLT stands for Distributed Ledger Technology. In the context of SMS in India, DLT refers to a blockchain-based registration system mandated by TRAI (Telecom Regulatory Authority of India) that records and verifies every business entity, sender ID, and message template used for commercial SMS.
Think of it as a central registry that all telecom operators share. When your business sends an SMS, the telecom operator checks the DLT registry: Is this business registered? Is this sender ID approved? Does this message match an approved template? If the answer to any of these is no, the message is blocked.
TRAI introduced DLT registration in 2018 and enforced it from 2021 to solve a specific problem: SMS spam. Before DLT, any business could send bulk SMS through aggregators without verification. Consumers were drowning in unsolicited messages — loan offers, insurance pitches, real estate ads — with no way to trace the sender. DLT registration creates accountability. Every commercial SMS sent in India is now traceable to a registered entity with verified identity documents.
Who Needs DLT Registration?
If your business sends any of the following SMS types to Indian phone numbers, you need DLT registration:
- Transactional SMS — OTPs, payment confirmations, order updates, delivery tracking, appointment reminders. These are triggered by a customer action and are informational in nature.
- Promotional SMS — Marketing offers, discount codes, sale announcements, new product launches. These are sent to customers for commercial purposes.
- Service SMS (Explicit) — Service updates, policy renewal reminders, account statements. These require explicit consent from the customer.
- Service SMS (Implicit) — Messages related to an ongoing transaction or relationship where consent is implied — like a bank sending a debit alert or an e-commerce platform sending an order shipped notification.
If you’re a bank, NBFC, insurance company, e-commerce business, EdTech platform, hospital, logistics company, SaaS product, or any business that communicates with Indian customers via SMS — you need DLT registration.
International businesses sending SMS to Indian phone numbers also need DLT registration. The regulation applies to the destination (India), not the origin of the business.
DLT Registration: The Complete Process in 5 Steps
Register as a Principal Entity on a DLT Portal
A “Principal Entity” (PE) is the business that owns the SMS communication — your company. You register your business on the DLT portal of any one telecom operator. You only need to register with one operator — the registration is shared across all operators via the distributed ledger.
Which operator to register with?
| Operator | Portal | Fee |
|---|---|---|
| Jio | trueconnect.jio.com | ₹5,900 |
| Airtel | dltconnect.airtel.in | ₹5,900 |
| Vodafone Idea (Vi) | vilpower.in | ₹5,900 |
| BSNL | ucc-bsnl.co.in | ₹5,900 |
| MTNL | ucc-mtnl.in | ₹5,900 |
Documents required:
- Business PAN card (for companies) or individual PAN (for sole proprietors)
- Certificate of Incorporation / Partnership Deed / GST certificate
- Authorized signatory’s Aadhaar or government-issued photo ID
- Company letterhead (for authorization letter)
- Email ID and mobile number of the authorized person
Registration process:
- Go to the DLT portal of your chosen operator and click “Register” or “Create Account”
- Select entity type: Company, LLP, Partnership, Sole Proprietor, Government, or Society
- Fill in business details: legal name, PAN, registered address, GSTIN, industry category
- Upload your identity and address proof documents
- Pay the one-time registration fee of ₹5,900 online
- Submit for approval — you will receive a unique Entity ID (PE ID) within 2–7 business days
After approval, you receive a unique Entity ID (also called Principal Entity ID or PE ID) . This is a permanent identifier for your business on the DLT registry. You’ll need this Entity ID when configuring your SMS provider — including when setting up SMS campaigns on EnableX.
Register with Jio or Airtel for the fastest approvals (2–3 days). BSNL uses manual review cycles and can take up to 7 days. Since you only register with one operator, pick the fastest one.
Register Your Sender ID (Header)
A Sender ID(also called a “Header”) is the name that appears as the sender when the recipient receives your SMS. For example, when you get an OTP from your bank and it shows “HDFCBK” or “ICICIB” — that’s the sender ID.
| Type | Format | Used For |
|---|---|---|
| Alphanumeric | Exactly 6 characters | Transactional & service SMS |
| Numeric | 10-digit number | Promotional SMS only |
Rules for Sender IDs:
- Must be exactly 6 characters for alphanumeric headers
- Cannot contain special characters or spaces
- Should represent your brand or business name
- Cannot be a generic word (e.g., OFFERS, DISCNT)
- Multiple sender IDs can be registered under one entity
Registration process:
- Log into your DLT portal and navigate to “Headers” or “Sender ID” section
- Click “Add New Header” and select type: Promotional or Transactional/Service
- Enter your desired 6-character sender ID
- Upload supporting documents (trademark certificate or brand ownership letter)
- Submit for approval — typically approved within 1–3 business days
Sender ID doesn’t match your business name or brand · Missing or invalid supporting documents · Using a generic or reserved word · Sender ID already registered by another entity.
Register and Get Templates Approved
Every SMS you send must match a pre-approved template registered on the DLT platform. You cannot send free-form text — the message content must conform to one of your approved templates.
| Category | Description | Example |
|---|---|---|
| Transactional | Triggered by customer action (OTP, alerts) | Your OTP is {#var#}. Valid for 10 minutes. Do not share. |
| Promotional | Marketing and sales messages | Flat 50% off on all products! Shop now at {#var#}. T&C apply. |
| Service Implicit | Service messages where consent is implied | Your order {#var#} has been shipped. Track: {#var#} |
| Service Explicit | Service messages requiring explicit consent | Your policy {#var#} is due for renewal on {#var#}. Renew now. |
Template rules:
- Use {#var#} for dynamic variables (names, amounts, OTPs, links)
- Content must match what you actually send — operators block mismatched messages
- No misleading or deceptive content
- Promotional templates cannot be sent to DND (Do Not Disturb) numbers unless you have Digital Consent
- URLs and phone numbers in templates must be whitelisted (see Step 4)
- Maximum 30 variables per template
Registration process:
- Log into your DLT portal and navigate to “Templates”
- Click “Add Template” and select the category: Transactional, Promotional, Service Implicit, or Service Explicit
- Select your industry category and the Sender ID this template will use
- Enter the template name and content body
- mark variables with{#var#}where dynamic data will be inserted
- Submit for approval — typically approved within 3–7 business days
After approval, each template gets a unique Template ID. You’ll need this Template ID when sending SMS through any provider — including EnableX’s SMS API.
Template content doesn’t match the selected category (e.g., promotional content in a transactional template) · Missing variable tags — if parts of the message change per recipient, they must be marked as `{#var#}` · URLs or phone numbers not whitelisted · Template resembles spam or misleading content
Whitelist CTAs — URLs and Phone Numbers
If your SMS templates contain any URLs (website links, payment links, tracking links) or phone numbers (callback numbers, helpline numbers), these must be whitelisted on the DLT platform. Un-whitelisted URLs and numbers will cause the SMS to be blocked.
process:
- Log into your DLT portal
- Navigate to “CTA Whitelisting” or “URL/Number Whitelisting”
- Enter the URL or phone number
- Select the template(s) this CTA is associated with
- Upload proof of ownership (domain registration, business letter)
- Submit for approval — typically approved within 1–3 business days
If you use URL shorteners (bit.ly, tinyurl), the shortened URL must also be whitelisted separately. Many businesses get their SMS blocked because they whitelist the full URL but not the short URL.
Complete Chain Binding
Chain binding connects your business (Principal Entity) with your SMS delivery provider (Telemarketer) on the DLT platform. Without this binding, the telemarketer cannot send SMS on your behalf, even if you have approved Entity ID, Sender ID, and Templates.
Your SMS provider (like EnableX) has their own Telemarketer Entity ID on the DLT platform. You need to “bind” your Principal Entity to their Telemarketer Entity.
process:
- Get your SMS provider’s Telemarketer Entity ID (for EnableX, contact [email protected])
- Log into your DLT portal — Navigate to “Chain Binding” or “Telemarketer Binding”
- Enter the Telemarketer Entity ID
- Select the Sender IDs and Templates you want to share with this telemarketer
- Submit the binding request — the telemarketer approves from their end within 24–48 hours
Once chain binding is complete, your SMS provider can send messages on your behalf using your approved Entity ID, Sender ID, and Templates. This is the final step before you can start sending SMS.
DLT Registration Charges: What Does It Cost?
| Item | Cost | Frequency |
|---|---|---|
| Entity registration | ₹5,900 | One-time |
| Sender ID (Header) registration | Free (included) | Per header |
| Template registration | Free (included) | Per template |
| CTA whitelisting | Free (included) | Per URL / number |
| Chain binding | Free (included) | Per telemarketer |
| Annual renewal | Varies by operator (₹0-₹5,900) | Annual |
The total upfront cost for DLT registration is ₹5,900. All subsequent registrations (headers, templates, CTAs, chain binding) are included at no additional charge.
DLT Registration Timeline: How Long Does the Whole Process Take?
Steps 2-4 can run in parallel after entity registration is approved. In practice, most businesses complete the entire process in 10–15 business days. If you want the registration done faster, EnableX offers a managed DLT registration service where our team handles the entire process on your behalf. Contact us for details →
DLT Registration: Operator-by-Operator Guide
Jio’s DLT portal is called “TrueConnect.” The interface is straightforward — entity registration, header registration, and template submission are all accessible from the main dashboard. Jio also has good customer support for DLT-related queries.
Airtel’s portal is “DLT Connect.” It’s widely used and well-documented. Airtel provides detailed error messages when templates are rejected, which helps with resubmission.
Vi’s DLT portal is called “VILPower” (or “SmartPing” for their SPARC API). The interface has more steps than Jio or Airtel, but the process is the same.
BSNL’s approval process tends to be slower due to manual review cycles. If speed is important, consider Jio or Airtel instead — remember, you only need to register with one operator.
Common Mistakes That Get DLT Applications Rejected
-
PAN mismatch — The PAN on your registration must match the business entity name exactly. Even a minor spelling difference causes rejection.
-
Promotional content registered as transactional — If your template says “50% off! Buy now!” but you registered it as transactional, it will be rejected. Be honest about the category.
-
Un-tagged dynamic variables — If any part of your SMS changes per recipient (name, OTP, amount, link), it must be wrapped in {#var#}. Missing even one variable causes rejection.
-
Un-whitelisted URLs — Every URL in your templates must be CTA-whitelisted. This includes URL shorteners, tracking links, and payment gateway URLs.
-
Generic sender IDs — “OFFERS”, “ALERTS”, “INFORM” — these get rejected. Your sender ID must represent your specific brand or business.
-
Not completing chain binding — You registered everything but forgot to bind with your SMS provider. Result: all messages blocked.
-
Using the wrong phone number format — Indian mobile numbers in templates should be in the format
+91XXXXXXXXXX. Inconsistency causes matching failures.
How to Send SMS After DLT Registration
Once your DLT registration is complete (Entity ID + Sender ID + Template ID + Chain Binding), you need an SMS delivery provider to actually send the messages. This is where EnableX SMS API comes in.
Using EnableX SMS API after DLT registration:
- Sign up on EnableX and create an SMS project
- Add your DLT credentials: Entity ID, Sender ID, and Template IDs
- Configure your webhook URL for delivery reports
- Start sending SMS through the API or Campaign Cloud dashboard
EnableX handles the DLT compliance checks automatically — every outgoing SMS is validated against your registered templates before delivery. If a message doesn’t match an approved template, the system flags it before it’s sent, saving you from operator-level blocking.
EnableX also supports multi-channel messaging — so after DLT registration for SMS, you can add WhatsApp Business API, RCS messaging, and voice broadcasting on the same platform, with the same API key and dashboard.
What to Do After DLT Registration
DLT registration gets you the credentials. To actually send SMS at scale, you need an SMS platform. Here’s what EnableX offers after your DLT registration is complete:
- SMS API — Programmatic SMS delivery with delivery reports, webhook callbacks, and DLT compliance validation. Send transactional, promotional, and OTP messages through a single API.
- Campaign Cloud — No-code dashboard for marketing and ops teams to create, schedule, and send bulk SMS campaigns without developer involvement.
- Multi-channel — Add WhatsApp Business API, RCS messaging, and voice broadcasting to the same platform. One dashboard, one API key, one billing account.
- Voice Broadcasting — After DLT for SMS, extend to AI-powered voice calls for EMI reminders, appointment confirmations, and delivery alerts.
