What is a DLT Sender ID (Header)?
A DLT Sender ID — also called a Header — is the name or number that appears as the sender on the recipient's mobile phone when they receive an SMS. Under TRAI's Distributed Ledger Technology (DLT) framework, every bulk SMS sent in India must originate from a pre-registered and approved Sender ID. Messages sent from unregistered or unapproved headers are blocked at the carrier level and never reach the intended recipient.
Examples of Sender IDs you may have seen:
- BLKSMS — a 6-character alphabetical transactional header
- HDFCBK — HDFC Bank transactional SMS
- 561234 — a 6-digit numeric promotional header
- AMAZON — order confirmation or OTP from Amazon
Key Rule: Sender IDs are case-sensitive.BLKSMSandblksmsare treated as two completely different Sender IDs on the DLT platform. Always enter the exact header as shown in your DLT approval screenshot.
Types of DLT Sender IDs
There are two distinct types of Sender IDs, each serving a different purpose:
| Type | Format | Use Case | Example |
|---|---|---|---|
| Transactional / Service | 6 alphabetical characters | OTPs, bank alerts, delivery notifications, order confirmations | BLKSMS, HDFCBK, AMAZON |
| Promotional | 6-digit numeric | Marketing campaigns, offers, product launches | 561234, 721890 |
What Does an Approved DLT Screenshot Look Like?
Once your Sender ID is approved on any DLT portal, the portal dashboard will show it with an APPROVED status. You must capture a clear screenshot of this for proof submission to your SMS provider.
The screenshot must clearly show:
- Your 6-character Header name (e.g.,
BLKSMS) - The APPROVED status label — not Pending, not Under Review
- The Entity name or PE ID linked to the header
Jio DLT (TrueConnect) Screenshot
Log in to trueconnect.jio.com, go to Header Management, and capture the row showing your header name alongside a green Approved badge. Key columns: Header Name, Status, Category.
Vodafone, BSNL, MTNL, Airtel Screenshot
On vilpower.in or dltconnect.airtel.in, navigate to the Sender ID section and take a screenshot showing: Header value, Status: Approved, Header Type (Transactional or Promotional).
Videocon DLT (Smartping / Pingconnect) Screenshot
Videocon's Smartping portal displays approved headers in a table. Capture the Header Name and the Approval Status showing Approved or Active.
Rules for Choosing a Valid Sender ID
- Must match your brand or business name — random or competitor names (e.g.,
GOOGLE) will be rejected. - Exactly 6 characters — no spaces or special characters.
- Alphabetical only for transactional — no digits in transactional headers.
- Numeric only for promotional — 6-digit numbers starting with the TRAI-assigned digit for your industry.
- Case-sensitive — always enter it in uppercase exactly as approved.
- Do not mix types — using a transactional header for promotional SMS causes immediate carrier-level blocking.
How to Register Your Sender ID on a DLT Portal
Step 1: Log in to your chosen DLT portal (Jio, Airtel, Vodafone, BSNL, or Tata Tele).
Step 2: Navigate to Header Management or Sender ID Management.
Step 3: Click Add New Header. Enter your 6-character header and select the type.
Step 4: Link the header to your registered Principal Entity (PE ID).
Step 5: Submit for review. Approval typically takes 24-48 hours.
Step 6: Once status shows APPROVED, capture a clear screenshot.
How to Submit Your Approved Sender ID to BlackSMS
- Log in to your BlackSMS dashboard.
- Click DLT Manager from the sidebar.
- Go to the Sender ID tab and click Add Sender ID.
- Enter your Entity ID, the exact Header name, and select the Category.
- Our team verifies and activates your Sender ID within 1 working day.
Pro Tip: You can also export a DLT Excel file of all your approved Sender IDs directly from your portal. BlackSMS accepts both screenshots and Excel exports as valid proof of approval.
Common Sender ID Errors and How to Fix Them
| Error | Cause | Fix |
|---|---|---|
| Message not delivered — Header mismatch | Sender ID in API differs from approved header (case or spelling) | Verify exact characters. BLKSMS is not the same as Blksms |
| Header registration rejected | Header does not match company name or trademark | Submit brand ownership proof, or choose a header derived directly from your business name |
| DLT scrubbing failure | Transactional header used to send a promotional message | Register a numeric promotional header and route marketing messages only through it |
| Status stuck at Pending | PE registration incomplete or document issue | Ensure your Principal Entity registration is fully approved before submitting headers |
Frequently Asked Questions
Q1. Can I use the same Sender ID with multiple SMS providers?
Yes. A DLT-approved Sender ID is universal across all telecom networks in India. You can use your approved header with BlackSMS or any other provider as long as the header and template IDs are correctly configured.
Q2. How many Sender IDs can I register?
There is no hard limit. Most businesses register 2-5 headers: one for OTP, one for transactional alerts, and one or more for promotional campaigns.
Q3. What happens if I send SMS without a registered Sender ID?
Messages with unregistered headers are filtered and blocked at the carrier level — they never reach the recipient. Your account may also be flagged or suspended for non-compliance with TRAI regulations.
Q4. Is the approval process different on different portals?
The core process is the same across all DLT portals. Timelines and UI differ slightly, but approved headers sync across all networks within 24 hours.
Conclusion
A properly registered and approved DLT Sender ID is the foundation of reliable SMS delivery in India. Whether you are sending OTPs, transactional alerts, or marketing campaigns, your header must exactly match the approved entry on your DLT portal. Follow the steps in this guide, capture a clear approval screenshot, and submit it to BlackSMS through the DLT Manager — our team will activate your sender within one working day.
Need help with DLT registration or Sender ID setup? Contact BlackSMS support — we provide end-to-end compliance assistance.