Guide
DLT registration for SMS in India: the complete guide
If you send SMS to Indian mobile numbers, DLT registration is not optional and there is no way around it. This guide walks through what DLT actually is, the three things you have to register, how long each takes, and the specific mistakes that cause messages to vanish without an obvious error.
What DLT is, in one paragraph
DLT stands for Distributed Ledger Technology. Under TRAI's TCCCPR regulations, every Indian telecom operator runs a DLT portal where commercial senders must register themselves, their sender IDs and their message content. When you submit an SMS, the operator checks it against that registry — a process called scrubbing — and drops anything that does not match.
The practical consequence: a message can be perfectly formed, sent through a working API, accepted by your provider, and still never arrive, because DLT rejected it. Most "my SMS isn't delivering" problems in India are DLT problems.
The three things you must register
They must be done in that order. You cannot register a header before your entity is approved, and you cannot register a template before you have a header to attach it to.
| What | Also called | Registered once per |
|---|---|---|
| Principal Entity | Entity ID, PE ID | Business — one registration, reused everywhere |
| Header | Sender ID | Traffic type — you may need separate headers for promotional and transactional |
| Content Template | Template ID, DLT template | Every distinct message format you send |
Step 1 — Register your entity
You register as a Principal Entity on any one operator's DLT portal. The major ones are Jio, Airtel, Vodafone Idea and BSNL. You do not need to register on all four — your entity ID propagates across operators once approved. Pick one and stay consistent.
- Use your legal registered name, not your brand name or trading name
- Documents must be clear scans; blurry uploads get rejected without a useful reason
- Keep the authorised person's contact details current — approvals and renewals go there
- Choose an operator portal and create an account with your official business email and phone.
- Enter your legal entity name exactly as it appears on your PAN or incorporation certificate. A mismatch here is the most common rejection.
- Upload your business documents — typically PAN, GST certificate or incorporation proof, and an authorised-signatory declaration on company letterhead.
- Nominate an authorised person and verify their email and mobile via OTP.
- Submit and wait for approval. You will receive a Principal Entity ID.
Step 2 — Register your header (sender ID)
The header is the six-character sender name your recipients see instead of a phone number. It is tied to a traffic type, and you cannot use a promotional header for transactional traffic or vice versa.
- Transactional, service-implicit and service-explicit headers are six alphanumeric characters — for example BRKTEL
- Purely promotional headers follow a numeric prefix convention set by the operator
- The header must plausibly relate to your registered entity name; unrelated headers get rejected
- Register separate headers if you send both marketing and transactional traffic — do not try to share one
- Some operators require a security deposit for promotional headers; check the portal you registered on
Step 3 — Register your content templates
Every distinct message format needs its own approved template. Variable parts are marked with placeholders; everything outside the placeholders is fixed text that must match your submission character for character.
A template looks like this:
- Choose the category carefully — Transactional, Service Implicit, Service Explicit or Promotional. This decides whether your message is scrubbed against DND.
- Variable placeholders have length limits, so a long dynamic value can silently break a match
- Do not put a variable at the very start of the message; many operators reject it
- Fixed text is matched exactly — an extra space, a changed comma, or a different case can fail the match
- Register one template per format, not one per message. A single OTP template serves all your OTPs.
Dear {#var#}, your BrookTel verification code is {#var#}.
Valid for 10 minutes. Do not share it with anyone.Choosing the right template category
Do not send marketing content on a transactional template to escape DND scrubbing. Operators audit this, and the penalty is losing your header — which takes your legitimate OTP traffic down with it.
| Category | Use for | DND scrubbing | Time restricted |
|---|---|---|---|
| Transactional | OTPs, banking transaction alerts | Exempt | No |
| Service Implicit | Order updates, receipts, reminders tied to a transaction | Exempt | No |
| Service Explicit | Content the user opted in to without transacting | Scrubbed against consent | No |
| Promotional | Offers, launches, marketing | Scrubbed against DND | Yes |
How long does DLT registration take?
Timelines are set by the operator portals, not by your SMS provider, and they vary. As a rough planning figure: entity approval usually takes a few working days, header approval a few working days after that, and template approval is often the fastest step once the first two are in place.
The single biggest cause of delay is a document or name mismatch that sends you back to the start. Get your legal entity name exactly right on the first submission and you will save yourself a week.
Why registered messages still fail
BrookTel validates your payload against your approved template before submission, so a mismatch comes back as an explicit API error with the reason rather than a message that quietly disappears.
| Symptom | Likely cause |
|---|---|
| Message rejected immediately | Template variable count does not match the approved template |
| Accepted but never delivered | Wrong template category, scrubbed against DND |
| Blocked at operator | Header not approved, or header/template pairing mismatched |
| Works for some numbers only | Recipient's operator has not synced your registration, or number is on DND |
| Worked yesterday, fails today | Template was edited on the DLT portal and needs re-approval |
| Fixed text mismatch error | A space, punctuation mark or case change versus the approved text |
Does WhatsApp need DLT?
No. DLT is a TRAI framework for SMS sent over Indian telecom operators. WhatsApp runs on Meta's platform and has its own approval system — message templates reviewed by Meta, with categories of marketing, utility and authentication.
The two systems are entirely separate. If SMS DLT approval is holding up your launch, WhatsApp is a way to start reaching customers in the meantime.
Frequently asked questions
What is DLT registration for SMS?
It is the mandatory registration of your business entity, sender ID header and message templates on a telecom operator's Distributed Ledger Technology portal, required under TRAI's TCCCPR regulations. Indian operators scrub every commercial SMS against this registry and block anything unregistered.
Do I need to register on all operator DLT portals?
No. Register as a Principal Entity on one operator's portal — Jio, Airtel, Vodafone Idea or BSNL — and your entity ID propagates to the others. Registering the same entity multiple times creates conflicts, not redundancy.
How long does DLT approval take?
It varies by operator and by how clean your submission is. Plan for a few working days for entity approval and a few more for header approval. Template approval is usually quicker. A name or document mismatch restarts the clock, so accuracy on the first attempt matters more than anything else.
Can I change a DLT template after it is approved?
You can edit it on the portal, but the edited template needs re-approval and your live sends will fail against the old version in the meantime. It is safer to register a new template and switch over once it is approved.
Why is my SMS failing with a template mismatch?
Because the fixed text you submitted does not exactly match the approved template, or the number of variables differs. Whitespace, punctuation and case all count. Compare your payload character by character against the approved version.
Is DLT registration free?
Entity and template registration is generally low-cost or free, but some operators require a security deposit for promotional headers. Check the specific portal you are registering on — the fees are set by the operator, not by your SMS provider.
Does BrookTel do DLT registration for me?
The registration has to be in your own business's name — that is the point of the framework, and no provider can legitimately do it as you. BrookTel is DLT-registered as a provider, stores your entity, header and template IDs, validates payloads against your approved templates, and guides you through the portal steps.