If you've tried to send OTPs, order alerts or promotional SMS in India, you've probably hit the word DLT. Without it, your messages simply don't get delivered — and operators won't tell your customers why.
This guide explains what DLT registration is, why it exists, and exactly how to get your business, sender IDs and templates approved — in plain English.
What is DLT?
DLT (Distributed Ledger Technology) is the registry Indian telecom operators use to control commercial messages. It was introduced under TRAI's Telecom Commercial Communications Customer Preference Regulations (TCCCPR), 2018, to cut spam and protect customers who don't want promotional messages.
Every business that sends SMS to Indian numbers must register three things on a DLT platform:
- Your business (called the Principal Entity, or PE)
- Your sender IDs (called headers)
- Your message templates (the exact text, with variable parts marked)
When you send an SMS, the operator checks that the header and the message text match what you registered. If they don't match, the message is blocked.
Who needs DLT registration?
Any business sending SMS to customers in India, including:
- e-commerce and D2C brands sending OTPs and order updates
- banks, NBFCs and fintech apps
- schools, colleges and coaching institutes
- clinics, hospitals and diagnostic labs
- real-estate developers, retailers and restaurants running promotions
If you only use WhatsApp or email, you don't need DLT for those — but most businesses still need SMS for OTPs and critical alerts.
Where to register
Each major operator runs a DLT portal — for example Jio, Airtel, Vodafone Idea (Vi), BSNL and Tata. You only need to register your business on one of them; the registration is shared across operators.
Pick the portal your SMS provider recommends — they'll often help you with the process and need to be linked to your account anyway.
Documents you'll need
Requirements vary slightly by portal, but keep these ready as clear scans:
- PAN card of the business (or the proprietor, for sole proprietorships)
- GST certificate — or another business proof such as a certificate of incorporation, shop and establishment licence or trade licence
- Letter of authorisation on company letterhead, naming the person who'll manage the DLT account (most portals give a format)
- ID proof of the authorised person
- Company email address and mobile number for OTP verification
There's a registration fee, which varies by operator — check the current fee on the portal you choose.
Step 1: Register your business (Principal Entity)
- Sign up on the DLT portal as a Principal Entity / Enterprise.
- Choose your business category and fill in the details exactly as they appear on your documents — legal name, PAN, GST, address.
- Upload the documents and pay the fee.
- Wait for approval. You'll receive a PE ID (Entity ID) — your SMS provider needs this.
Most rejections happen because the name on the application doesn't match the documents, or the authorisation letter is missing a signature or stamp.
Step 2: Register your headers (sender IDs)
The header is what customers see as the sender. In India it appears with a short operator prefix, for example VM-YRBRND.
- Service and transactional headers are usually six letters, like
YRBRND. Choose something close to your brand name so customers trust it. - Promotional headers are numeric (six digits) and are assigned or chosen as per the portal's rules.
You may need to show that the header relates to your brand. Avoid generic words or other companies' names — they get rejected.
Step 3: Register consent templates (if needed)
If you'll send service messages that need explicit consent — for example, a follow-up to someone who filled a form — you register a consent template that describes how customers agreed to hear from you. Your provider can tell you whether you need this for your use case.
Step 4: Register content templates
Every message you send must match a registered content template. Templates are grouped into categories:
| Category | Used for |
|---|---|
| Promotional | Offers and marketing; not delivered to people on the DND list |
| Transactional | OTPs from banks for completing transactions |
| Service – implicit | OTPs, order and account alerts a customer expects |
| Service – explicit | Messages that need the customer's prior consent |
Write your template with the fixed text exactly as it'll be sent, and mark the changing parts with variables:
Dear {#var#}, your order {#var#} has been shipped and will reach you by {#var#}. Track it here: {#var#} - YourBrand
Tips that get templates approved first time:
- Pick the right category. A discount offer is promotional, even if it's sent after a purchase.
- Keep the fixed text meaningful. A template that's mostly variables gets rejected.
- Include your brand name in the text.
- Whitelist your links and numbers. URLs, app links and call-back numbers used in messages must be registered with the template. Messages with links that aren't whitelisted are blocked.
Step 5: Link your SMS provider (telemarketer)
Your SMS provider is registered as a telemarketer (TM) on DLT. You'll add them to your account (often called binding or declaring the delivery chain) so messages sent through them can be traced back to you. Since late 2024, operators block messages where this chain isn't declared properly — so if your messages suddenly stop, check this first.
Step 6: Test, then go live
Send test messages to a few numbers on different operators. If a message fails, compare the exact text with your template — an extra space, a changed word or an unregistered link is usually the reason.
Promotional SMS: extra rules
- Promotional SMS isn't delivered to numbers registered on DND (Do Not Disturb) for that category, unless the customer has given consent.
- Promotional messages can only be sent during the hours the rules allow.
- Always include a way to opt out.
Common reasons messages fail after DLT
- The message text doesn't exactly match the approved template.
- The header used isn't linked to that template.
- A link or phone number in the message isn't whitelisted.
- The provider (telemarketer) isn't properly linked to your entity.
- A promotional template is being sent to DND numbers.
SMS, WhatsApp or both?
SMS reaches every phone without an app, which makes it ideal for OTPs and critical alerts. WhatsApp is better for conversations, rich order updates and campaigns. Most businesses use both: WhatsApp first, SMS as the fallback.
Let us handle the paperwork
Our SMS and DLT registration service prepares your documents, registers your entity, headers and templates, sets up OTP and alert routes, and connects SMS to your store or CRM — so your messages are delivered from day one.