How to register a header and template on DLT: step-by-step guide

Every business that sends commercial SMS to Indian mobile numbers has to be registered on a DLT (Distributed Ledger Technology) platform run by the telecom operators. If your header or template is not registered, or the message does not match the template, operators block it before it reaches the customer. This guide walks through the whole process in the order you will actually do it.

Step 1: Register your business as a Principal Entity

Pick any one operator DLT portal (Jio, Airtel, Vi, BSNL and others each run one) and register as a Principal Entity (PE). Registration on one portal is shared with all operators, so you only do this once.

• Business PAN and GST certificate (or other proof of business)
• Authorisation letter on company letterhead for the person registering
• Email and mobile number of the authorised person
• A one-time registration fee, which varies by portal

Approval usually takes a few working days. Once approved you get a DLT Entity ID (PE ID). Keep it handy, because your SMS provider needs it on every message.

Step 2: Register your headers (sender IDs)

A header is the sender name customers see, such as AD-TXTNSM. There are two kinds:

• Transactional and service headers: 6 letters, ideally linked to your brand name (for example TXTNSM). Avoid generic words like OFFERS or INFORM.
• Promotional headers: 6 digits, usually allotted by the portal.

Since May 2025 operators also add a suffix to the header based on the template type: -P promotional, -S service, -T transactional and -G government. You do not register the suffix; it is added automatically.

Step 3: Register content templates

A content template is the exact text of your message, with variable slots marked as {#var#}. Every SMS you send must match one approved template word for word, except inside the variable slots.

1. Choose the category: promotional, service or transactional. Mixing promotional words into a service template is a common reason for rejection.
2. Link the template to the right header.
3. Write the fixed text and mark variables with {#var#}. Keep variables only where the content truly changes, such as a name, amount or OTP.
4. Whitelist every URL and callback number used in the template. Messages with links that are not whitelisted are blocked.

Example of a good transactional template: "Dear {#var#}, your order {#var#} has been shipped and will arrive by {#var#}. Track: {#var#} - TXTNSM"

Step 4: Consent templates

For messages that rely on the customer's explicit consent, register a consent template too. It describes how and where the customer agreed, so the operator can verify it. Rules for consent-based categories changed under TRAI's 2025 amendment, so confirm the current options on your DLT portal.

Step 5: Connect it to your SMS provider

Share your DLT Entity ID, approved headers and template IDs with your SMS provider. In TextNSMS you add them once in your dashboard, and every campaign is checked against them before sending, so a mismatched message is stopped before it costs you anything. See how it works on our Bulk SMS page.

Common reasons templates get rejected

• Promotional words (offer, discount, sale) inside a transactional or service template
• Too many variables, or a variable covering the whole message
• URL shorteners or links that are not whitelisted
• Header that does not match the brand or the template category
• Spelling or formatting that differs from what you later send

Frequently asked questions