If your business sends OTPs, order updates, reminders or promotional SMS in India, every one of those messages must pass through a DLT check before it reaches the customer. Messages that do not match a registered entity, header and template are simply blocked by operators. DLT registration can feel intimidating the first time, but it follows a clear sequence. This step-by-step guide explains what DLT is, what you need and how to register headers and templates correctly so your messages flow without interruption.
What Is DLT and Why Does It Exist?
DLT stands for Distributed Ledger Technology. Under TRAI’s regulations on unsolicited commercial communication, telecom operators run blockchain-based DLT platforms that record every business sending commercial messages (the Principal Entity), its sender IDs (headers), its message templates, its consent records and the telemarketers it works with. When your message is sent, the operator checks it against these records in real time, a process called scrubbing. Then, if everything matches, the operator delivers the message. If not, it is rejected.
Overall, the goal is to cut spam and fraud, make every commercial message traceable to a registered business and ensure customers’ preferences are respected. For a broader compliance overview, see our TRAI DLT and consent checklist for 2026.
Key DLT Terms You Should Know
| Term | Meaning |
|---|---|
| Principal Entity (PE) | The business that sends the message, such as your company |
| Telemarketer (TM) | The SMS service provider or aggregator that delivers your messages |
| Header / Sender ID | The name or number shown as the sender |
| Content template | The pre-approved message format with fixed text and variables |
| Variable | A placeholder, written as {#var#}, for dynamic values like names, amounts or OTPs |
| Scrubbing | The real-time check operators perform before delivering a message |
| PE-TM binding | The registered link between your entity and the telemarketers allowed to send on your behalf |
What You Need Before DLT Registration
- Business PAN card
- GST certificate, TAN or other business registration proof as applicable
- Letter of authorisation on company letterhead naming the person managing registration
- Authorised person’s ID proof
- Business email address and mobile number for OTP verification
- Proof supporting your brand name for header registration, such as a trademark or website, where required
Step 1: DLT Registration as a Principal Entity
- Firstly, choose any one operator’s DLT portal. Registration on one operator’s platform is shared across the DLT ecosystem, so you do not need to register separately with each operator.
- Select “Enterprise” or “Principal Entity” as the registration type.
- Then enter company details, upload documents and pay the registration fee, which varies by operator.
- After verification, typically within a few working days, you receive a unique Entity ID. Finally, share this with your SMS provider.
Step 2: DLT Registration for Sender Headers
A header is the sender name customers see. Rules differ by message category:
- Transactional and service messages: Alphabetic headers of six characters, such as VENERA or MYBANK, closely related to your brand name.
- Promotional messages: Numeric headers assigned or registered for promotional use.
Tips for header approval:
- Also, choose a header clearly linked to your brand or business name. However, generic words and names of other brands are rejected.
- Also, register separate headers for different business units or brands if needed.
- Pick the correct category for each header; the category determines how and when messages are delivered.
Headers also carry a category suffix visible to customers, helping them distinguish promotional, service, transactional and government messages at a glance.
Step 3: DLT Registration for Content Templates
Every message you send must match a registered template. In short, a template has fixed text and variables.
Example of a good template
Dear {#var#}, your order {#var#} has been shipped and will be delivered by {#var#}. Track: {#var#} – VENERA
When registering a template:
- Select the header it will be used with.
- Choose the template type: transactional, service implicit, service explicit or promotional.
- Enter the fixed text and insert {#var#} wherever content will change.
- Specify whether the message is in English or a regional language (Unicode).
- Submit and note the Template ID once approved.
Template Writing Rules That Prevent Rejections
- Keep fixed text meaningful: Templates made up almost entirely of variables are rejected. The fixed text must make the purpose clear.
- Do not mix categories: Promotional content in a service template is a common rejection reason.
- Respect variable limits: Each variable has a character limit, so do not plan to insert whole paragraphs into one variable.
- Match exactly when sending: Spacing, punctuation and line breaks in the fixed text must match the registered version.
- Include your brand name so customers recognise the sender.
- Avoid misleading language or anything that looks like phishing.
Step 4: Whitelist URLs, APKs and Call-Back Numbers
Messages containing links, app download links or call-back numbers are delivered only if those URLs and numbers are whitelisted on DLT. Register the exact domains and link shorteners you use, and use a whitelisted, branded short-link domain where possible. Unregistered links are one of the most frequent reasons for sudden delivery failures.
Step 5: Complete PE-TM Chain Binding
For traceability, the path your message takes from your business through each telemarketer to the operator must be declared on DLT. Add your SMS provider and any aggregators they use as authorised telemarketers against your Entity ID. If the chain is incomplete, messages can be rejected even when headers and templates are correct. Your provider will tell you which telemarketer IDs to add.
Step 6: Share IDs with Your Provider and Test
Give your SMS provider your Entity ID, headers and Template IDs. Most providers map them automatically in their dashboard or API. Send test messages for every template, including edge cases like long names and different amounts, and confirm delivery reports show success.
Troubleshooting Common DLT Registration Errors
| Problem | Likely cause | Fix |
|---|---|---|
| Message rejected for template mismatch | Fixed text differs from registration | Copy the registered template exactly; re-register if content must change |
| Header not found | Header not approved or wrong category | Check header status and category on the portal |
| Link messages failing | URL not whitelisted | Whitelist the domain or short-link used |
| All messages suddenly failing | Incomplete PE-TM chain or expired registration | Verify telemarketer bindings and entity status |
| Promotional SMS not reaching some users | Customer preferences or time window | Send within permitted hours; respect preferences |
To safeguard your OTP traffic as well, review how to protect your SMS budget from pumping fraud.
Keeping Your DLT Registration Healthy
- Review templates quarterly and deactivate ones you no longer use.
- Keep a central register of headers, Template IDs and their owners inside your company.
- Update whitelisted URLs whenever you change domains or link shorteners.
- Renew entity registration and update documents when company details change.
- Train marketing teams not to edit template text on the fly.
The rules come from TRAI, so check its site for the latest directions.
Frequently Asked Questions
How long does DLT registration take?
Entity registration usually takes a few working days after document submission. Header and template approvals are often faster, sometimes within a day, but can take longer during busy periods.
Do I need to register on every operator’s DLT portal?
No. Registering on one operator’s platform is generally sufficient, as data is shared across the DLT network.
Can I use one template for multiple headers?
Templates are linked to specific headers. If you send the same content from multiple headers, register or link the template accordingly.
Does DLT apply to WhatsApp or RCS?
DLT applies to SMS and commercial voice calls on telecom networks. WhatsApp and RCS have their own template approval and verification processes.
Get DLT-Ready with Venera Connect
Venera Connect guides businesses through DLT entity, header and template registration, handles PE-TM binding and monitors delivery so your messages keep flowing. Explore our SMS solution or talk to our team.