Not all bulk SMS is treated the same under India's DLT/TRAI framework. Promotional SMS vs transactional SMS comes down to different delivery windows, different DND rules, and different registration paths. Here's how they compare.
Delivery Window and DND
Promotional SMS can only be sent between 9 AM and 9 PM, and is blocked to numbers registered on the DND (Do Not Disturb) list. Transactional SMS is exempt from both restrictions, it can be sent 24x7, even to DND-registered numbers, since it relates to a transaction or service the customer already opted into.
Winner for reach: Transactional, but only for transaction-related content, it cannot be used for marketing.
Content and Use Cases
Promotional SMS covers offers, discounts, new product announcements, and marketing campaigns. Transactional SMS covers OTPs, order confirmations, delivery updates, payment receipts, and appointment reminders, content tied to a specific transaction or service the customer initiated.
This isn't a competition, it's a classification that determines which rules apply to your message.
DLT Registration and Templates
Both require DLT (Distributed Ledger Technology) registration under TRAI's framework, entity registration, sender ID (header) registration, and template registration are mandatory for both categories. The difference is in template category tagging: promotional templates are flagged Promotional, transactional templates are flagged Service Transactional, and this tag determines which delivery rules apply.
Winner: Tie, the registration overhead is similar either way.
Delivery and Filtering
Promotional SMS from unregistered or mismatched senders gets filtered by telecom operators far more aggressively, DND scrubbing alone blocks a large share of numbers. Transactional SMS, properly registered, sees near-100% delivery since operators treat it as essential communication.
Winner for guaranteed delivery: Transactional.
Frequently Asked Questions
Can I send offers as transactional SMS to avoid DND restrictions?
No. This violates TRAI regulations, and registered senders face blocking or blacklisting for misclassifying promotional content as transactional.
Do I need separate sender IDs for promotional and transactional SMS?
Not necessarily the same header, but templates must be correctly tagged by category during DLT registration regardless of which sender ID is used.
Not Sure Which Category Your Messages Fall Under?
Getting the classification wrong risks blocked messages and DLT penalties. Get in touch and we'll help you register and classify your templates correctly on our SMS Marketing platform.