DLT registration is the process of enrolling your business on India’s blockchain-based messaging compliance platform, run by telecom operators under rules set by the Telecom Regulatory Authority of India (TRAI). Any organization that sends bulk SMS to customers, whether promotional offers, transaction alerts, or one-time passwords, must complete this registration before a single message goes out. The legal foundation is the Telecom Commercial Communications Customer Preference Regulations, 2018, tightened significantly by amendments in 2025. Once registered, every commercial message you send is traceable back to your verified identity, and the network will block anything that does not match a pre-approved template.
Who Has to Register
Two categories of participants use the DLT platform, and you need to know which one applies to you before you start.
A Principal Entity is the organization whose name and brand appear in the message. That covers private companies, government departments, educational institutions, hospitals, NGOs, and sole proprietorships. If your organization originates the message content and decides who receives it, you are a Principal Entity, even if a third-party platform actually transmits the SMS.
A Telemarketer, in this context, is not a cold-caller. Telemarketers are aggregators, SMS gateway providers, and cloud communication platforms that deliver messages on behalf of Principal Entities. After you register as a Principal Entity, you must “chain” each Telemarketer you plan to use for delivery. Without that chain link, the Telemarketer cannot transmit messages under your headers.
Documents You Need Before You Start
Gather these before opening the registration form:
- PAN card of the business. The name must match exactly across every document you upload.
- GST certificate. The registered address on the GST certificate becomes your verified business address on the DLT platform.
- Letter of Authority designating who can manage the DLT account for the organization. Most telecom portals provide a downloadable template.
- Business category. You will pick a primary industry (finance, healthcare, retail, education, government, and so on) during registration. Choose the one that matches your GST filing.
- A valid email address and mobile number. Your Entity ID is sent to these after approval.
Government entities follow a slightly different path. They may submit a TAN in place of a PAN card, and the authorization letter for central government departments is typically coordinated through the Centre for Development of Advanced Computing (C-DAC).
How to Complete Registration
Registration happens on one telecom operator’s DLT portal. The major portals are run by Jio, Airtel, Vodafone-Idea (Vi), and BSNL. Choosing one does not lock you into that carrier for delivery. Your messages can still travel through any network once you are registered, and if you later register on additional operator portals, those secondary registrations are typically free.
The sequence is predictable. Go to the signup page on your chosen portal and select the Principal Entity option. Fill in your entity name exactly as it appears on your PAN and GST documents, because even minor discrepancies trigger rejection during the manual audit. Upload digital copies of your PAN, GST certificate, and Letter of Authority in the formats the portal accepts, usually PDF or JPEG. Pay the one-time registration fee, which runs approximately ₹5,900 including taxes on most platforms.
After submission, the operator’s compliance team manually reviews your application. This typically takes two to three business days. Once approved, you receive a unique Entity ID. Keep it secure. This is the permanent identifier you will need for every subsequent step: registering headers, submitting templates, and linking telemarketers.
Registering Headers (Sender IDs)
A header is the sender name that appears on the recipient’s phone when your message arrives. It is not a phone number. TRAI defines a header as an alphanumeric string of up to eleven characters, and the portal assigns the operator-and-circle prefix. Your brand identifier, up to six characters, sits after a hyphen.
Under the 2025 amendments, headers must also carry a suffix indicating the message category: -P for promotional, -T for transactional, -S for service, and -G for government messages sent under TRAI-exempted headers. This suffix requirement took effect in May 2025 and makes the message type visible to both the network and the recipient.
Each header must be separately registered and approved on your DLT portal. The approval process checks that your header does not impersonate an existing brand or government agency. Once approved, the header is linked to your Entity ID and can only be used with content templates registered under that same ID.
Registering Content Templates
Every SMS you send through the DLT system must match a pre-approved content template. You cannot send free-form text. A content template has fixed text (the parts of the message that never change) and variable placeholders where personalized data gets inserted, such as a customer’s name, an OTP code, or a transaction amount. The standard variable format is {#var#}.
A bank’s OTP template, for example, might read: “{#var#} is the OTP for your transaction of INR {#var#} with your card ending {#var#}. Valid for {#var#} minutes. Do not share with anyone.” The fixed text locks the message structure, and each variable gets replaced with real data at the moment of sending.
You submit each template through your DLT portal for approval. Once cleared, the system generates a unique Template ID that must be included in the message metadata during transmission. If the outgoing message does not match an approved template stored on the ledger, the telecom network blocks it automatically. No approved template, no delivery.
Consent Templates and Customer Permission
Content templates govern what you say. Consent templates govern your right to say it. A consent template is the standardized format you use to obtain a customer’s permission before sending certain types of messages. It does not contain the message text; it lays out the terms under which the customer agrees to receive communications from you.
Not every message type requires a consent template:
- Transactional messages (OTPs, payment confirmations, delivery updates triggered by a customer’s own action) do not require prior promotional consent.
- Service messages require consent when they involve commercial elements beyond pure service delivery.
- Promotional messages always require explicit consent obtained through a registered consent template.
Consent is not permanent. Under the 2025 amendments, explicit consent for service messages tied to a commercial transaction lasts only seven days unless TRAI directs otherwise. For longer relationships, consent cannot extend beyond the duration of the underlying contract between sender and recipient. When the contract ends, so does your permission to message that customer.
How Consent Scrubbing Works
Before a promotional message reaches a subscriber, it goes through consent scrubbing. The system checks the message against two databases: the national Preference Register, where subscribers record their DND preferences and block specific message categories, and the Consent Register, where explicit customer permissions are stored.
If a subscriber has blocked promotional messages and the sender has no explicit consent on record, the message gets dropped. But if the sender holds valid explicit digital consent from that subscriber, the message goes through regardless of DND preferences. That is the practical reason consent templates matter: properly acquired and registered consent is the only way to reach customers who have otherwise opted out.
Consent data collected by Principal Entities must be shared on the DLT platform so that all telecom operators can perform this scrubbing check. Messages from senders who are not registered on the DLT platform at all are automatically classified as unsolicited commercial communication.
Message Categories and Delivery Rules
TRAI classifies commercial messages into distinct categories, each with different delivery rules. Getting the category wrong can result in blocked messages or regulatory action.
- Transactional (-T). Messages triggered by a customer’s own action, such as OTPs, order confirmations, and account alerts. Deliverable at any time, including nights and weekends.
- Service (-S). Messages related to an existing customer relationship that include some informational or semi-commercial content, such as policy renewal reminders or account statements. Delivery timing is more relaxed than promotional but tighter than transactional.
- Promotional (-P). Marketing offers, discount codes, new product announcements, and any message whose primary purpose is selling. Subject to delivery time windows, and must respect DND preferences unless explicit consent overrides them.
- Government (-G). Messages from government entities operating under TRAI-exempted headers. These must still flow through the DLT platform.
The old “Service Explicit” category has been discontinued under the 2025 amendments. Templates previously registered under that category have migrated to Promotional and now carry the -P suffix.
Penalties for Non-Compliance
TRAI does not treat DLT violations as paperwork issues. The consequences escalate quickly and can shut down an organization’s communication infrastructure.
For unregistered senders, any commercial message is treated as unsolicited commercial communication. On the first violation, outgoing services on all of the sender’s telecom resources, including SIP trunks, PRI lines, and SIM cards, are barred by all operators for fifteen days, even if those specific resources were not used to send the offending messages. On a second violation, all telecom resources are disconnected for one year, the sender is blacklisted across all operators (no new connections during that period), and the devices used to send the messages are blocked network-wide for one year.
Registered senders who misuse their headers or templates face a different but equally disruptive process. If a registered entity’s headers or templates are found compromised or misused, all traffic from that sender is suspended across every operator until the entity files a complaint with law enforcement, reviews all its headers and templates, and takes corrective measures. Failure to periodically re-certify registration details, headers, and templates leads to automatic suspension.
What Changed in 2025
The Telecom Commercial Communications Customer Preference (Second Amendment) Regulations, 2025, published in February 2025, introduced several changes that affect how entities operate on the DLT platform going forward.
- All headers must now carry a category suffix (-P, -T, -S, or -G), making the message type transparent to both the network and the recipient.
- The Service Explicit category no longer exists. Templates in that category have been migrated to Promotional and are now subject to stricter consent and delivery rules.
- Explicit consent for service messages tied to a commercial transaction expires after seven days. Contract-based consent expires when the contract ends.
- Government communications must now flow through the DLT platform, closing a gap that previously existed for public-sector messaging.
The core regulations took effect thirty days after publication, with specific provisions around complaint handling and enforcement taking effect after sixty days. If you registered before these amendments, review your headers, templates, and consent records against the new rules before your next re-certification.