New TRAI SMS Header Rules: What Businesses Must Know Before May 6, 2025

The Telecom Regulatory Authority of India (TRAI) has announced a critical regulatory change for businesses using A2P (Application to Person) SMS services. Starting May 6, 2025, all A2P SMS messages must include a suffix in the sender header to clearly indicate the type of message being delivered. This move is aimed at enhancing transparency, user awareness, and message classification.

If you are a business using bulk SMS for marketing, transactional alerts, or customer service updates, this change directly impacts how your messages will appear on customers' phones.

What is the New TRAI Requirement?

As per the 2nd Amendment issued on February 12, 2025, TRAI has mandated that all Telecom Service Providers (TSPs) implement a system that automatically appends a suffix to SMS headers during the DLT (Distributed Ledger Technology) scrubbing process.

These suffixes are based on the content type of the message template:

• -P : Promotional
• -S : Service (both Implicit and Explicit)
• -T : Transactional
• -G : Government (TRAI-exempted only)

Why is TRAI Introducing This Change?

The primary aim of this update is to:

• Improve transparency for message recipients
• Prevent message misuse and confusion
• Help users distinguish between promotional, service, and transactional content
• Standardize SMS communication across telecom networks

How Will This Work in Practice?

Let’s break it down with a real-world example:

1. Header Registered on DLT: ABCXYZ
2. Template Type: Service Implicit
3. Message Delivered As: AD-ABCXYZ-S

Here,

• AD = Operator and Circle Code
• ABCXYZ = Original Header
• S = Service type

This suffix is not manually added by the business; it is automatically appended by the TSP during DLT scrubbing, based on the classification of the registered template.

Understanding Suffix Mapping

Suffix	Message Type	Example Use Cases
-P	Promotional	Offers, Discounts, Campaigns
-S	Service (Implicit/Explicit)	Notifications, Reminders, Info Updates
-T	Transactional	Order Confirmations, Payment Alerts
-G	Government	Govt Schemes, Official Notices (Exempt)

What Do Businesses Need to Do?

• Ensure Your Templates Are DLT-Compliant: Double-check that all your message templates are registered and approved with the correct type (Promotional, Service, Transactional).
• Check Headers in Use: Review your SMS headers and understand that suffixes will be added automatically.
• Inform Your Teams and Customers: Help your internal teams and even your customers understand why headers will now include “-P”, “-S”, or “-T”.
• Choose the Right Provider: Work with a bulk SMS provider like Shree Tripada that ensures full TRAI and DLT compliance, and offers support through every regulatory update.

Will This Affect Message Delivery or Pricing?

No, this change does not affect the delivery rate or pricing of your SMS messages. It is purely a compliance and transparency update that ensures better communication standards across telecom networks.

Benefits of This Regulation

• Enhanced transparency and trust for end users
• Clear classification of messages for legal and operational clarity
• Improved monitoring and control by TRAI

Conclusion

This TRAI update is a step toward building a more transparent and secure A2P messaging ecosystem. As a business owner, marketer, or telecom reseller, it’s important to stay updated and ensure compliance before the May 6, 2025 deadline.

For more information or assistance with DLT registration and SMS compliance, contact Shree Tripada today.