TRAI has announced the rollout of an end-to-end routing traceability mechanism for commercial SMS in India. Effective December 11, 2024, commercial SMS messages for which the transmission chain has not been registered and bound will be rejected for delivery by telecom operators. The measure requires enterprises, banks, government agencies and other principal entities, as well as the SMS aggregators and delivery service providers they engage, to register the complete transmission path of messages from the sending source to the final operator on the blockchain-based DLT platform.
TRAI previously issued a directive on August 20, 2024, requiring full-chain traceability of commercial communications to be implemented starting November 1. Due to the large number of participating enterprises, the regulator extended the deadline first to November 30 and then to December 10, to allow approximately 113,000 active principal entities to complete onboarding. The enterprises involved span banking, insurance, healthcare, real estate, government services and other industries that rely heavily on SMS notifications.
The term "chain registration and binding" refers to the requirement that enterprises register the message flow path between themselves, their aggregators, delivery telemarketers and operators in the DLT system. This enables the system to identify the originator of a given commercial SMS, the service providers through which it is transmitted, the sender ID and content template used, and trace the responsible entity in the event of spam, fraud, number misuse or complaints. The mechanism also restricts enterprises from delivering messages via unreported grey routes.
TRAI adopted a "tag first, reject later" approach during the transition period. Initially, the system returned error codes for SMS messages routed through unregistered paths, but did not block them immediately, to avoid sudden disruption of bank OTPs, transaction alerts and other time-sensitive information. Operators forwarded error notifications to enterprises to assist them in correcting their registration details; once the majority of enterprises completed onboarding, the regulator officially launched the interception of messages via unregistered routes.
This measure, together with other governance tools such as URL whitelisting, disconnection of communication resources for non-compliant senders, and the migration of telemarketers using the 140 number range to the DLT system, forms India's anti-spam SMS framework. Enterprises are required to continuously maintain records of sender identities, templates, links, user consents and transmission chains; DLT registration information must also be updated promptly in the event of any change of aggregator, route or delivery service provider.
