India DLT

India’s telecom regulator (TRAI) requires every commercial SMS to be traceable to a registered sender and a registered template. The registration happens on a Distributed Ledger Technology (DLT) portal run by the Indian operators. Once registered, you receive three identifiers. Vobiz lets you attach them to every message and broadcast you send to Indian numbers.

Building with code? DLT IDs are fields on Send a message and on broadcasts in the Messaging API.

Vobiz records the identifiers you supply on each message. Register your entity, headers and templates on a DLT portal first; the operators check each message against that registration.

The three identifiers

Field	What it is	Where it comes from
`dltEntityId`	Your Principal Entity ID: the identity of the business sending the message.	Issued when your organisation completes entity registration on a DLT portal.
`dltHeaderId`	The registered sender header (the 6-character alphanumeric sender ID recipients see, for example `ACMEIN`) and its ID.	Issued per header you register under your entity. Transactional, service and promotional headers are registered separately.
`dltTemplateId`	The ID of the registered content template your message text follows.	Issued per template. A template fixes the wording and marks the variable positions.

The message text must match the registered template, with the variable positions filled in. For example, if the template is

Dear {#var#}, your OTP for Acme is {#var#}. Valid for 10 minutes.

then the text you send must be that sentence with the two variables replaced, for example Dear Jane, your OTP for Acme is 482913. Valid for 10 minutes. Operators reject messages whose text does not match a template registered under the header you used, and messages with no DLT data at all.

Pass the IDs on a message

Add the three fields to POST /messages. They are stored on the message record alongside the rest of the request.

curl -X POST "https://api.vobiz.ai/api/v1/sms/messages" \
  -H "X-Auth-ID: MA_XXXXXXXX" \
  -H "X-Auth-Token: YOUR_AUTH_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "ACMEIN",
    "to": ["+919876543210"],
    "text": "Dear Jane, your OTP for Acme is 482913. Valid for 10 minutes.",
    "dltEntityId": "1101234567890123456",
    "dltHeaderId": "1105123456789012345",
    "dltTemplateId": "1107123456789012345",
    "idempotencyKey": "otp-482913-919876543210"
  }'

import requests

BASE = "https://api.vobiz.ai/api/v1/sms"
HEADERS = {
    "X-Auth-ID": "MA_XXXXXXXX",
    "X-Auth-Token": "YOUR_AUTH_TOKEN",
    "Content-Type": "application/json",
}

r = requests.post(
    f"{BASE}/messages",
    headers=HEADERS,
    json={
        "from": "ACMEIN",
        "to": ["+919876543210"],
        "text": "Dear Jane, your OTP for Acme is 482913. Valid for 10 minutes.",
        "dltEntityId": "1101234567890123456",
        "dltHeaderId": "1105123456789012345",
        "dltTemplateId": "1107123456789012345",
        "idempotencyKey": "otp-482913-919876543210",
    },
)
r.raise_for_status()
print(r.json()["id"], r.json()["status"])

const BASE = "https://api.vobiz.ai/api/v1/sms";
const headers = {
  "X-Auth-ID": "MA_XXXXXXXX",
  "X-Auth-Token": "YOUR_AUTH_TOKEN",
  "Content-Type": "application/json",
};

const res = await fetch(`${BASE}/messages`, {
  method: "POST",
  headers,
  body: JSON.stringify({
    from: "ACMEIN",
    to: ["+919876543210"],
    text: "Dear Jane, your OTP for Acme is 482913. Valid for 10 minutes.",
    dltEntityId: "1101234567890123456",
    dltHeaderId: "1105123456789012345",
    dltTemplateId: "1107123456789012345",
    idempotencyKey: "otp-482913-919876543210",
  }),
});
if (!res.ok) throw new Error(await res.text());
const message = await res.json();
console.log(message.id, message.status);

The ID values above are placeholders. Use the values your DLT portal shows for your entity, header and template.

Keep one template ID per message shape in your code, and build the text from the same string you registered. Drift between the two is the most common reason an Indian operator rejects a message.

Pass the IDs on a broadcast

POST /broadcasts and PUT /broadcasts/{id} take the same three fields, each up to 64 characters. Every recipient’s message is sent with them.

{
  "name": "October statement reminder",
  "from": "ACMEIN",
  "template": "Dear {{name}}, your Acme statement for {{month}} is ready at https://example.com/statements.",
  "dltEntityId": "1101234567890123456",
  "dltHeaderId": "1105123456789012345",
  "dltTemplateId": "1107123456789012346"
}

The broadcast template uses {{variable}} placeholders filled from the columns of the uploaded recipient file. Make sure the result, after substitution, still matches the DLT template registered under dltTemplateId. The Broadcasts guide covers uploads, preview and launch.

Sender IDs and numbers for India

Indian A2P traffic is sent from registered alphanumeric headers, not from long-code phone numbers. GET /numbers/available?country=IN returns an empty list with the hint India uses DLT sender IDs, not long codes, and POST /numbers/purchase for an Indian number returns 422 with the same message. Register your header on a DLT portal and contact support@vobiz.ai to have it enabled as a from value on your account.

Checklist before you send to India

Entity registered on a DLT portal and dltEntityId recorded.
Header registered for the right category (transactional, service or promotional) and dltHeaderId recorded.
Template registered under that header, dltTemplateId recorded, and your message text reproduces it exactly with variables filled.
Promotional traffic respects the recipient’s Do Not Disturb preference and the permitted sending window. See UCC and NDNC compliance.
Opt-outs handled on your side as well: a recipient who texts STOP is recorded in opt-outs and subsequent sends to them return 422.

Build it with the Messaging API

Send a message

Pass dltEntityId, dltHeaderId and dltTemplateId.

Broadcasts

Set DLT IDs once for a whole send.

Sending SMS

Segments, idempotency and statuses.

Opt-outs

Honour STOP replies on every channel.

India calling regulations

TRAI and DoT requirements for voice traffic in India.

India number KYC

Identity verification for Indian numbers on Vobiz.

UCC and NDNC

Do Not Disturb registry and unsolicited commercial communication rules.

Next steps

Send a message

Full request schema including the DLT fields.

Broadcasts

Bulk sends with DLT IDs on every recipient.

Getting Started

Using Vobiz Platform

Messaging (SMS & RCS)

Compliance (India)

Tools

The three identifiers

Pass the IDs on a message

Pass the IDs on a broadcast

Sender IDs and numbers for India

Checklist before you send to India

Build it with the Messaging API

Send a message

Broadcasts

Sending SMS

Opt-outs

India calling regulations

India number KYC

UCC and NDNC

Next steps

Send a message

Broadcasts

​The three identifiers

​Pass the IDs on a message

​Pass the IDs on a broadcast

​Sender IDs and numbers for India

​Checklist before you send to India

​Build it with the Messaging API

Send a message

Broadcasts

Sending SMS

Opt-outs

​Related Vobiz India compliance pages

India calling regulations

India number KYC

UCC and NDNC

​Next steps

Send a message

Broadcasts

The three identifiers

Pass the IDs on a message

Pass the IDs on a broadcast

Sender IDs and numbers for India

Checklist before you send to India

Build it with the Messaging API

Related Vobiz India compliance pages

Next steps