What DLT is, and why it exists
The Distributed Ledger Technology (DLT) platform is TRAI’s system for registering every commercial sender, sender ID and message template used in India, so that regulators and operators can trace who sent what, on whose behalf, and with what consent. Any business sending transactional or promotional SMS or making automated voice calls at scale needs to register on it before traffic will deliver reliably.
Principal entity registration
Your business registers once as a Principal Entity with your operator of choice, using standard KYC — company PAN, GST, incorporation documents and an authorised signatory. This entity ID is the anchor every header and template is bound to afterwards.
Sender ID (header) registration
A header is the 6-character sender ID your messages appear from (e.g. MSGBRG). Headers must be alphabetic, must reasonably represent your brand name, and are registered against your entity ID before any template can use them.
Content template registration and variable rules
Every message body is registered in advance as a template with variables marked in curly braces, e.g. Your OTP is {{1}}. Valid for {{2}} minutes.. The static text and variable positions must match exactly what you send at runtime — even a stray full stop can cause a mismatch and a blocked message.
Template categories
Templates are registered under a category — Transactional, Promotional or Service Explicit/Implicit — which determines which routes and time windows they can send on, and how they are treated for consent and DND purposes.
TM chain binding
The Telemarketer (TM) chain binds your entity, your header and your approved templates to the specific operator route carrying your traffic. Without this binding in place, an otherwise-approved template will still fail to deliver.
Consent and opt-in records
For promotional and certain service messages, you need a retrievable record of consent — when and how the customer opted in. Keep this against the same identifiers you register on DLT so it can be produced if an operator or TRAI ever asks for it.
DND scrubbing
Numbers registered on the National Do Not Disturb (NDNC) registry are automatically scrubbed from promotional sends. Transactional and consented service messages are exempt, which is exactly why template categorisation matters.
What gets messages rejected, and how to fix it
- Variable mismatch — the live payload doesn’t match the registered template text exactly. Fix: log the exact registered string and diff against what your code sends.
- Wrong category for the route — a promotional-style message sent on a transactional route. Fix: re-register the template under the correct category.
- Header not bound to the template — TM chain binding incomplete. Fix: confirm binding status before going live, not after the first send fails.
- Consent not on file — an operator audit finds no opt-in record for a promotional send. Fix: keep consent logs from day one, not retroactively.
Realistic timelines at each stage
Entity registration and header approval typically move within a few working days once documents are complete. Template approval is usually the fastest step when the content is drafted correctly the first time. Operator queues vary and are outside any platform’s direct control — build in buffer before a hard launch date.