DLT Registration for SMS in India: Entity, Header and Template Steps

If your business sends SMS to Indian mobile numbers, whether OTPs, appointment reminders, payment updates or offers, you need to be registered on DLT. Without it, telecom operators block your messages before they reach the customer, and you usually find out only when customers say nothing arrived. DLT registration for SMS sounds bureaucratic, but it follows a clear sequence: register your business, register your sender headers, register your message templates, then send only what you registered.

This guide explains what DLT is, walks through each registration step, lists the most common reasons for rejection and explains what it all means when you send SMS from a CRM. Rules and portal screens change from time to time, so always check the current requirements on your operator's DLT portal.

What is DLT?

DLT stands for Distributed Ledger Technology. Under TRAI's Telecom Commercial Communications Customer Preference Regulations, 2018 (TCCCPR), India's telecom operators keep a shared, blockchain-based registry of the businesses that send commercial messages, their sender IDs, their approved message templates, and customers' consent and preferences. Enforcement for SMS tightened in 2021, and operators now check each commercial SMS against this registry before delivering it, a step usually called scrubbing.

The aim is to cut spam and fraud. For a business, the effect is simple: an SMS that doesn't match a registered entity, header and template does not get delivered.

Who's who on DLT

Step 1: Register your business as a Principal Entity

Choose one operator's DLT portal. Jio, Airtel, Vodafone Idea (Vi) and BSNL each run one, and a registration on one portal is shared across operators, so you don't need to register everywhere. Your SMS provider may suggest a portal.

You will typically need:

• your business PAN
• a GST certificate or another proof of business registration
• a letter of authorisation for the person registering, in the portal's format
• the authorised person's ID proof, email address and mobile number

Operators charge a registration fee that varies by portal. Once your documents are verified, you receive your Principal Entity ID. You will give it to your SMS provider and enter it in any software that sends SMS on your behalf.

Step 2: Register your sender headers

A header is the sender name shown on the customer's phone. For service and transactional messages, headers are six letters and should clearly relate to your brand or business name. A company called Sharma Steel Traders, for example, might register SHRMST. Promotional messages use a numeric header instead.

Register only the headers you will actually use, and keep them recognisable. Customers are more likely to trust, and less likely to report, a sender they can identify.

Step 3: Register your content templates

Every message you send must match a registered template. A template is your message wording with {#var#} placeholders for the parts that change, such as a name, an amount or a date. Each variable can hold up to 30 characters. For example:

Dear {#var#}, your site visit at {#var#} is confirmed for {#var#}. Our executive will call you before the visit. - Sharma Realty

When you register a template, you choose the header it will be sent from and its category:

Choose the category honestly. A discount offer registered as service implicit breaks the rules even if it slips through approval, and it can be blocked or flagged later.

Step 4: Whitelist links and link your SMS provider

TRAI has tightened the rules on links in SMS. URLs, app download links and similar content in your templates generally need to be whitelisted on the DLT portal, and messages carrying unregistered links can be blocked. If your messages include payment links, booking pages or app links, register those domains as well.

Your SMS provider, the telemarketer, must also be linked to your entity on the portal, along with the chain of providers that carries your messages, because TRAI now requires that delivery chain to be declared. Your provider will normally tell you exactly what to add.

Common reasons DLT registrations are rejected

• A header unrelated to your brand. A generic header, or one that doesn't match your entity name, is a frequent rejection.
• The wrong template category. Promotional wording submitted as service or transactional.
• Too many variables. A template that is mostly {#var#}, or uses a variable for text that never changes, looks as if it could carry anything and is often rejected.
• The brand name missing. Some operators expect the business or brand name in the template text.
• Links that aren't whitelisted. Especially links from public URL shorteners.
• Document mismatches. The business name on the PAN, the GST certificate and the authorisation letter doesn't match what was entered on the portal.

One more problem isn't a registration rejection but causes most blocked SMS: the message actually sent doesn't match the registered template. A changed word, extra text or a variable filled with more than 30 characters is enough.

What DLT means for sending SMS from a CRM

Once you are registered, whichever system sends your SMS, whether a CRM, a billing system or a marketing tool, has to follow the same rules:

• Your PE ID and template ID travel with every message. The sending system needs your entity ID and the right template ID for each message.
• The wording must match the template. Only the {#var#} parts can change. If a rep edits the message freely, it will probably be blocked.
• Merge fields must fit the variables. A CRM field such as a customer's full name or a long product name must fit the 30-character limit of each variable.
• Promotional timing is enforced. Promotional templates can only go out between 10:00 and 21:00 IST, so automated campaigns need to respect that window.
• Opt-outs still matter. DLT handles DND preferences at operator level, but you should still honour STOP replies and keep your own do-not-contact list.
• New wording means a new template. Plan campaigns early enough to allow for approval.

A practical tip: keep one list of every registered template with its ID, header, category and exact wording. When a message is blocked, the first thing to check is whether what was sent matches that wording exactly.

How DigiPix Flow handles DLT

DigiPix Flow does not register on the DLT portal for you; your business does that with its operator. Once you are approved, you add your Principal Entity ID and register your templates in DigiPix Flow with their template ID, six-character sender header, category and approved wording. Texts to Indian numbers are matched against your active templates, and you can switch on a rule that refuses any SMS that matches none. Promotional templates are held outside 10:00 to 21:00 IST, and STOP replies withdraw consent. The SMS integration page covers setup, WhatsApp and SMS covers day-to-day messaging, and consent and opt-outs explains how STOP is handled.

Register once, then send with confidence

DLT registration takes some effort up front, but it is mostly a one-time job: register your entity, a few recognisable headers and the templates you actually use. After that the discipline is simple. Send only what you registered, in the category you registered it under, at the times that category allows.