Bulk SMS API · DLT & compliance

SMS DLT Registration & Sender ID Approval

In India, SMS can be sent only after DLT registration, Sender ID (header) approval and template approval. Here's how the process works — and Laabam guides you through every step, free.

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Important: SMS delivery may be blocked or rejected by telecom operators until DLT registration, Sender ID approval and template approval are all complete. Sending is enabled only after every required approval.

The DLT approval process, step by step

1

Register your Principal Entity

Register your business as a Principal Entity (Enterprise) on a DLT platform with your legal name and business documents (GST/PAN as applicable). You receive a PE ID.

2

Register your Sender ID / Header

Request the 6-character header customers will see (for example, LBMONE). It must reflect your business, brand or product name. Promotional and transactional headers are approved separately.

3

Register your SMS templates

Submit each exact message format with variable placeholders. Only DLT-approved templates can be sent — the delivered text must match the approved template.

4

Complete telemarketer / platform mapping

Map your header and templates to the sending platform where required, so operators can route your traffic.

5

Start sending

Once DLT registration, Sender ID and templates are approved and mapped, SMS sending is activated. We enable it on your Laabam account.

Sender ID / Header

The name recipients see — for example LBMONE. It must match your business, brand or product name and be approved on the DLT platform before you can send with it.

Template approval

Every message must match an approved template. Example:

Dear {#var#}, your OTP for login is {#var#}. Please do not share this OTP with anyone. - LBMONE

Promotional vs transactional SMS

Promotional SMS

  • Marketing, offers, campaigns and product announcements
  • Subject to DND / customer preference rules
  • Uses an approved promotional header and template
  • Time-of-day restrictions apply per TRAI rules

Transactional / Utility SMS

  • OTP, payment alerts, order & booking updates, service alerts
  • Delivered to all numbers including DND
  • Must not contain marketing or promotional content
  • Uses an approved transactional/utility header and template

What we'll need from you

Have these ready and our team submits your registration for you.

  • Company / business legal name
  • GST / PAN / registration details (where applicable)
  • Authorized person details
  • Website or brand proof (where applicable)
  • Requested Sender ID / header
  • SMS template samples
  • Consent details (where applicable)

Once approved, send via the Laabam API

Pass your approved sender ID, template ID and PE ID with each request:

curl -X POST https://api.laabam.one/v1/messaging/{company}/sms \
  -H "X-Client-Id: lk_id_..." \
  -H "X-Client-Secret: lk_secret_..." \
  -H "Content-Type: application/json" \
  -d '{
    "to": "919800000000",
    "message": "Your OTP for login is 123456",
    "sender_id": "LBMONE",
    "template_id": "1707xxxxxxxxxxxxx",
    "pe_id": "1101xxxxxxxxxxxxx",
    "type": "transactional"
  }'
Full SMS API reference

DLT registration — free with Laabam

We guide you through Principal Entity, Sender ID and template approval at no extra charge. Get sending sooner.

Register on Laabam.app