What is Transactional SMS? 

In a world where communication is key, businesses must deliver real-time information to their customers. One of the fastest and most reliable tools to achieve this is Transactional SMS. Unlike promotional messages, these are essential, service-based messages that are delivered 24×7—even on DND (Do Not Disturb) numbers.

What is Transactional SMS?

Transactional SMS refers to messages sent by businesses to customers that contain important information related to their accounts, transactions, or services. These are non-marketing messages and are typically automated.

Example:
“Dear Rahul, your OTP for login is 456321. Do not share this with anyone. – ABC Bank”

These messages are allowed to be sent 24/7, including to users who are registered under DND.  

Key Features of Transactional SMS

Feature	Details
Purpose	Share account info, alerts, OTPs, updates
Time	Delivered 24×7
DND Delivery	Yes, sent even to DND-registered users
Content Approval	Must follow template-based messaging (TRAI compliant)
Sender ID	Fixed 6-character alphanumeric (e.g., AB-ICICIB)
Speed	High-priority routes ensure instant delivery
Personalization	Messages can include user names, order IDs, OTPs, etc.

 Difference Between Transactional and Promotional SMS

Feature	Transactional SMS	Promotional SMS
Purpose	Info, alerts, service updates	Marketing, discounts, offers
Delivery Time	24/7	Only between 9 AM to 9 PM
DND Delivery	Allowed	Not allowed
Sender ID	Fixed and registered	Random 6-character code
Content	Informational, no marketing language	Promotional language
Use Cases	OTPs, Order status, Account alerts	Sales promotions, new product alerts

 Who Can Use Transactional SMS?

Transactional SMS is ideal for:

• Banks & NBFCs – Sending OTPs, transaction alerts

• E-commerce – Order status, shipping alerts

• Healthcare – Appointment confirmations, test results

• EdTech – Exam results, login alerts

• Logistics – Delivery updates

• Apps & SaaS – Login codes, usage alerts 

TRAI Guidelines for Transactional SMS in India

To prevent misuse and ensure privacy, TRAI has made it mandatory for all businesses to follow these rules:

1. DLT Registration Required
   Every business must register on the Distributed Ledger Technology (DLT) platform to send transactional SMS.

2. Sender ID Must Be Fixed
   Use a 6-character alphanumeric ID like “AB-HDFCBK” for brand recognition.

3. Template Approval
   All transactional message formats must be submitted for approval before usage.

4. Consent Not Required for Transactional SMS
   You can send transactional SMS to users without explicit opt-in as long as it’s strictly informational.   
   
   Benefits of Using Transactional SMS

•  Instant Delivery: Reaches users in real-time within seconds.  

• DND-Friendly: Goes through even if the number is in the Do Not Disturb list.  

• Better Customer Trust: Users trust SMS for security-sensitive data like OTPs.  

• Trackable: Delivery reports help in auditing and debugging.  

• Secure: End-to-end encrypted SMS routes protect sensitive data.  
  
  How to Set Up Transactional SMS for Your Business

1. Register on a DLT Platform

2. Use any DLT portal like:

   • Jio DLT (https://trueconnect.jio.com)

   • Airtel DLT (https://dltconnect.airtel.in)

   • Vodafone (https://smart.dlt.vodafoneidea.com)

3. Get Sender ID Approved
   Submit your 6-character header like ABCDEF.

4. Create Message Templates
   Define static and dynamic parts (e.g., Hello [Name], your OTP is [OTP]).

5. Choose an SMS Provider
   Select a trusted bulk SMS gateway that supports high-priority transactional SMS 

6. Integrate with API
   Most services offer HTTP or REST APIs to send messages directly from your app or website.  
   
   Examples of Transactional SMS Templates

1. OTP Template
   "Dear [Name], your OTP is [OTP]. Do not share it with anyone."

2. Order Confirmation
   "Hello [Name], your order #[Order_ID] has been confirmed. Estimated delivery: [Date]."

3. Appointment Reminder
   "Reminder: You have an appointment with Dr. [Doctor Name] at [Time], [Date]."  

   Best Practices for Transactional SMS

•   Never include sensitive data like passwords  

• Use personal names to increase engagement  

• Avoid marketing language, even subtly  

• Track delivery logs regularly  

• Test templates before going live  
  Common Mistakes to Avoid  

• Sending promotional content in transactional messages  
• Ignoring DLT compliance  
• Using unregistered sender IDs  
• Skipping message approval  

Conclusion

Transactional SMS plays a critical role in enhancing trust and providing real-time updates to your customers. Whether you’re running a small e-commerce business or managing a fintech platform, these messages ensure your customers stay informed and engaged at every step.

With TRAI-compliant practices and the right bulk SMS gateway, you can build a strong communication system that works 24/7. 

FAQs

Q1. Can I send marketing content in transactional SMS?
No, it must be purely informational. Promotional content is not allowed.

Q2. Do I need customer consent to send transactional SMS?
Not necessarily, as long as the message is service-related and the user is registered.

Q3. Is DLT registration mandatory for transactional SMS?
Yes, as per TRAI, it is required to avoid penalties and ensure delivery.

Q4. How many characters can I send in one SMS?
Up to 160 characters. More than that is broken into multiple SMS segments.

Q5. Can I use the same sender ID for promotional and transactional SMS?
No, sender IDs are separate and approved for specific categories.