Introduction

DLT Rules & Compliance for Bulk SMS in India, the Distributed Ledger Technology (DLT) framework is the backbone of commercial communication. Introduced by the Telecom Regulatory Authority of India (TRAI), its mission is simple: to eliminate spam, prevent phishing, and ensure that every business message is traceable and consented.

However, as of 2025, the rules have become even more stringent. New mandates regarding header suffixes, “Principal Entity-Telemarketer” (PE-TM) chain binding, and stricter content scrubbing are now in full effect. For a small business or a large enterprise, staying compliant isn’t just about following the law—it’s about ensuring your critical OTPs and promotional offers actually reach your customers’ inboxes.

This guide breaks down the essential 2025 DLT updates, the registration process, and the “Common Rejection” traps you must avoid to keep your mobile marketing ROI high.

Major 2025 DLT Updates: What’s New?

If you haven’t updated your DLT practices since last year, you are likely at risk of message blocking. Here are the critical changes for 2025:

A. Mandatory Header Suffixes (Effective May 2025)

To improve transparency, TRAI now mandates that every SMS header (Sender ID) must include a suffix indicating the message type.

• -T for Transactional: (e.g., TRUBNK-T) Used for OTPs and immediate transaction alerts.
• -P for Promotional: (e.g., ZYLKER-P) Used for marketing and offers.
• -S for Service: (e.g., HLTINS-S) Used for reminders and non-promotional updates.
• -G for Government: (e.g., GOVIND-G) Reserved for authorized government communications.

B. PE-TM Chain Binding

Businesses (Principal Entities) must now formally “bind” or link their account with their specific Bulk SMS Provider (Telemarketer) on the DLT portal. This ensures a clear line of traceability from the business to the mobile operator.

C. Pre-Tagging of Variables

Operators now enforce “Pre-tagging” in content templates. You must clearly define variable parts (like {#var#}) in your templates. Any message that doesn’t exactly match the approved structure will be automatically dropped during the “Scrubbing” process.

The Step-by-Step DLT Registration Process

Registration is mandatory for everyone—startups, NGOs, and corporations alike.

1. Select a Portal: Choose one telecom operator’s DLT portal (Jio, Airtel, Vi, BSNL). Note: You only need to register on one portal; your data will sync across all Indian networks.
2. Entity Registration: Register as a “Principal Entity” (PE). You will need:
   • Business Proof: GST Certificate, PAN Card, or Certificate of Incorporation.
   • Authorization: A Letter of Authorization on company letterhead for the person managing the account.
3. Header (Sender ID) Registration: Apply for your 6-character alphanumeric headers.
   • Promotional: Must be numeric.
   • Transactional/Service: Must be alphabetic.
4. Content Template Registration: Submit the exact text of your messages for approval. This can take 24–72 hours.
5. Consent Template Registration: If sending promotional SMS, you must register a “Consent Template” explaining how and why you acquired the user’s phone number.

Understanding SMS Categories under DLT

Choosing the wrong category is the #1 reason for template rejection.

Category	Definition	Example
Transactional	Only for OTPs required to complete a transaction initiated by the customer.	“Your OTP for login is 1234.”
Service Implicit	Necessary updates related to a product or service already purchased.	“Your order #555 has been shipped.”
Service Explicit	Messages sent with consent that contain both information and a slight promotional nudge.	“Your policy expires soon. Renew now and get 5% off!”
Promotional	Purely marketing content sent to non-DND numbers or with explicit consent.	“Flash Sale! 50% off on all items today only.”

Common DLT Rejection Reasons & Fixes

• Variable Misuse: Using {#var#} for entire sentences. Variables should only be for short, dynamic data like names, dates, or amounts.
• Missing Brand Name: TRAI mandates that every message must include your registered Brand Name or Trademark at the end.
• Wrong Category: Submitting a promotional offer under the “Transactional” category to bypass DND rules. This will lead to immediate template rejection and potential account suspension.
• Low-Quality Documents: Uploading blurry or expired GST/PAN documents. Ensure all scans are high-resolution and valid.

DLT Compliance Checklist for Businesses

• [ ] Is your Business Entity (PE) registered and verified?
• [ ] Have you linked your Telemarketer (PE-TM Chain)?
• [ ] Are your Headers updated with the new 2025 suffixes (-T, -S, -P)?
• [ ] Does every message template include your Brand Name?
• [ ] Are you scrubbing your promotional lists against the National DND registry?

Simplify Your Compliance with DialMeNow

Navigating TRAI’s evolving regulations is a complex, time-consuming task. One small mistake in a template can lead to your entire marketing campaign being blocked.

We offer end-to-end DLT Support and Managed SMS Services.

• ✅ Expert DLT Assistance: We guide you through the initial registration and KYC process to ensure 100% approval.
• ✅ Template Optimization: Our team reviews your message templates to ensure they meet the latest variable and brand-name requirements.
• ✅ Automatic Header Management: We handle the technical suffix mapping so your messages always appear correctly to the end user.
• ✅ Real-Time Compliance Monitoring: We stay updated on TRAI changes so you don’t have to.

Don’t let red tape stop your business growth.

Frequently Asked Questions (FAQ)

Q1: Is DLT registration mandatory for international businesses?

A: Yes. If you are an international entity sending SMS to Indian mobile numbers, you must complete the DLT registration process via an Indian telecom operator.

Q2: How much does DLT registration cost in 2025?

A: Most operators (Jio, Airtel, Vi) charge a one-time registration fee of approximately ₹5,900 (including GST). Some government-owned operators like BSNL may have lower fees.

Q3: Can I use the same Header for both Transactional and Promotional SMS?

A: No. Promotional headers must be numeric (e.g., 456789), while Transactional/Service headers must be alphanumeric (e.g., TRUBNK).

Q4: How long does the DLT registration process take?

A: Typically, Entity approval takes 48–72 hours. Header and Template approvals usually take an additional 24–48 hours each.

Q5: What happens if I send SMS without DLT registration?

A: Your messages will be blocked by the telecom operators. Continued attempts can lead to your business being blacklisted and legal penalties from TRAI.

Q6: What is “Scrubbing”?

A: Scrubbing is the automated process where the operator’s system checks your message against your registered DLT templates and the user’s DND status before delivery.

Q7: Can I change my Brand Name after registration?

A: You can register additional brand names/headers, but the primary Entity name should match your legal business documents.

Q8: Do Transactional messages need DND scrubbing?

A: No. Transactional and Service Implicit messages (OTPs, alerts) are delivered to all users, regardless of their DND (Do Not Disturb) status.

Disclaimer

The information provided in this guide is based on the TRAI TCCCPR (2018) regulations and the 2025 amendments as of the current date. Telecom regulations in India are subject to frequent change. We recommend consulting with a certified telecom aggregator or the official TRAI website for the most current legal requirements.

Conclusion

DLT compliance in 2025 is no longer just a “one-time setup”; it is an ongoing operational requirement. By embracing the new suffix rules, ensuring strict template matching, and maintaining clear traceability, businesses can protect their brand reputation and ensure their communications are effective. Stay compliant, stay transparent, and your customers will reward you with their trust.