What is an SMS Sender ID?
A Sender ID is what your customer sees in the "From" field when they receive your SMS — instead of a random mobile number, they see your brand name. It is the single most visible element of any business SMS.
When your bank sends you an OTP, you see HDFCBK or SBIINB — not a random mobile number. When Amazon sends an order confirmation, you see AMAZON. When Swiggy sends a delivery alert, you see SWIGGY. That name — the 6-character alphabetic identifier displayed in place of the sender's phone number — is the Sender ID, also officially referred to in TRAI regulations as the Header.
In India, all commercial SMS Sender IDs must be registered on the TRAI DLT platform under your business's Principal Entity (PE) account before any messages can be sent. An unregistered Sender ID will be blocked at the telecom operator's DLT scrubbing layer — your SMS will never be delivered regardless of how correct the template or PE registration is. Sender ID registration is one of the four mandatory DLT compliance steps alongside PE registration, template registration, and PE–TM Binding Chain.
You can register multiple Sender IDs under a single PE account — for example, one Sender ID for Transactional SMS (OTP, order alerts) and a separate one for Promotional SMS (offers, campaigns). Each Sender ID is registered under a specific SMS category (Transactional, Promotional, Service Implicit, or Service Explicit) and can only be used to send that category of SMS — using a Transactional Sender ID to send Promotional content, or vice versa, is a TRAI violation.
📱 How your SMS appears on a customer's phone:
Top: Transactional Sender ID | Bottom: Promotional Sender ID
🔑 Why Sender ID Matters
- Customers recognise your brand immediately
- OTP SMS from branded IDs have higher completion rates
- Customers are less likely to ignore or delete branded SMS
- Reduces phishing risk — customers know it's genuinely you
- TRAI compliance — mandatory for all commercial SMS
- Builds long-term brand trust with your customer base
SMS Sender ID Rules — TRAI DLT
TRAI sets strict rules for Sender ID format, registration, and usage. Violating these rules results in immediate message blocking and potential PE suspension.
✓ Sender ID Rules — What is Allowed
- Exactly 6 alphabetic characters — A to Z only
- Must represent your registered business name or brand
- Can be an abbreviation of your brand (e.g. FIVOSM for Fivo SMS)
- Multiple Sender IDs allowed under one PE registration
- Separate Sender IDs for each category: Transactional, Promotional, Service Implicit, Service Explicit
- Can use the same 6 characters across categories if registered separately for each
- Approval granted by each telecom operator independently
✗ Sender ID Rules — What is NOT Allowed
- Numbers (0–9) — Sender IDs must be alphabetic only
- Special characters, spaces, or hyphens
- Fewer than or more than exactly 6 characters
- Names that impersonate another registered brand (e.g. AMAZON if you're not Amazon)
- Generic words without brand connection (e.g. OFFERX, SALEMS)
- Using a Transactional Sender ID to send Promotional content
- Using an unregistered Sender ID — messages will be blocked
- Offensive or misleading brand names
Transactional vs Promotional Sender ID — Key Differences
| Parameter | Transactional Sender ID | Promotional Sender ID |
|---|---|---|
| SMS Category | OTP, order alerts, payment receipts, booking confirmations, account security | Sale offers, new launches, festive campaigns, loyalty rewards, event invitations |
| DND Numbers | ✓ Can send to DND-registered numbers | ✗ Cannot send to DND-registered numbers |
| Time Window | ✓ 24 hours × 7 days — no restrictions | ✗ 10:00 AM – 9:00 PM IST only |
| Prefix on Phone | No prefix — shows as plain 6-character ID | No prefix — shows as plain 6-character ID |
| DLT Registration | ✗ Mandatory on DLT as "Transactional" | ✗ Mandatory on DLT as "Promotional" |
| Typical Examples | HDFCBK, FIVOSM, SWIGGY, IRCTCO | RETLBR, FASHON, SALEXX, OFFRMX |
| Content Mixing | ✗ Cannot include promotional offers in Transactional SMS | ✗ Cannot include service alerts in Promotional SMS |
| Opt-in Required | ✓ No explicit marketing opt-in needed | ✗ Explicit customer opt-in required |
Example Sender IDs — Common Indian Businesses
⚡ Transactional Sender IDs
HDFC Bank
OTP, account debit/credit alerts, net banking login notifications, loan EMI deduction SMS
Swiggy
Order placed, order picked up, out for delivery, delivered confirmation, OTP for app login
IRCTC
Ticket booking confirmation, PNR status, cancellation confirmation, refund initiated SMS
Fivo SMS
Account OTP, credit balance alert, API usage notification, invoice and payment confirmation
🎉 Promotional Sender IDs
Myntra
EOSS sale launch, new collection announcement, loyalty reward alert, festive offer campaign
D-Mart
Weekend offer SMS, new product arrival, store opening announcement, discount campaign
MagicBricks
New project launch, site visit offer, pre-launch booking invitation, property price update
BYJU'S (EdTech)
New course launch, limited seat offer, scholarship campaign, free demo class invitation
How to Register a Sender ID on DLT — Step by Step
Sender ID registration is done on the TRAI DLT portal under your Principal Entity account. It cannot be done before completing PE registration. Here is the exact process.
Complete PE Registration First
Sender ID registration requires an approved Principal Entity (PE) account on a TRAI DLT portal (Vodafone, Airtel, Jio, BSNL, or Videocon). If you have not yet registered as a PE, complete that step first — PE approval takes 1–3 business days. Full DLT Registration Guide >>
Choose Your Sender ID — 6 Characters
Choose a 6-character alphabetic name that clearly represents your brand. It must be unique on the DLT system — if another business has already registered the same 6-character ID as the same SMS category, you cannot use it. Have 2–3 alternatives ready. Good approach: abbreviate your full brand name (FivoSMS → FIVOSM, Reliance → RIANCE, HDFC Bank → HDFCBK). Avoid generic words.
Log In to DLT Portal & Navigate to Header Registration
Log in to your DLT portal with your PE credentials. Navigate to the "Header" or "Sender ID" registration section (the exact name varies by portal — Vodafone calls it "Header Registration", Airtel calls it "Sender ID"). Select "New Header" or "Add Sender ID".
Enter Sender ID Details & Select Category
Enter your 6-character Sender ID exactly as you want it to appear on customer phones. Select the SMS category: Transactional (for OTP, alerts, confirmations), Promotional (for marketing campaigns), Service Implicit, or Service Explicit. You must register a separate Sender ID for each category you intend to use. Provide the business justification for the Sender ID if the portal requests it.
Await DLT Approval
Sender ID approval by the DLT portal typically takes 24–72 hours. Some portals (especially Airtel DLT) approve within a few hours for straightforward brand-name Sender IDs. You will receive an approval or rejection notification via the DLT portal dashboard and email. Rejection reasons commonly include: ID already taken by another PE, generic name not tied to a brand, or name that appears to impersonate a known brand.
Link Sender ID to Fivo SMS & Start Sending
Once approved, provide your registered Sender ID to Fivo SMS as part of your account setup. Complete the PE–TM Binding Chain to link your PE to Fivo SMS on the DLT portal. Your registered Sender ID is now ready to use — select it when creating campaigns in your Fivo SMS panel or pass it as a parameter in the API call. PE–TM Binding Chain Guide >>
- Sender ID already registered by another business on the same DLT portal
- Name appears to impersonate a well-known brand (e.g. GOGLXX suggesting Google)
- Generic or dictionary word with no clear brand connection
- Contains numbers or special characters (only A–Z permitted)
- Not exactly 6 characters
How Fivo SMS Helps with Sender ID Registration
📄 Sender ID Review Before Submission
Before you submit your Sender ID on the DLT portal, Fivo SMS reviews your proposed name for likely rejection issues — checking if it's already taken, if it follows naming rules, and if it clearly represents your brand. This saves days of back-and-forth caused by avoidable rejections. Most customers get their Sender ID approved on first submission when they use Fivo SMS's guided onboarding.
👥 Multiple Sender ID Management
Fivo SMS supports multiple Sender IDs within a single account — route different SMS types through the correct registered Sender ID automatically. Define which Sender ID to use per SMS category, per campaign, or per API call. For businesses sending both Transactional and Promotional SMS, Fivo SMS ensures the correct Sender ID is used for each message type, keeping your DLT compliance intact across every send.
🔗 Full DLT Onboarding Support
Sender ID registration is step 2 of the 4-step DLT compliance process — after PE registration and before template registration and PE–TM Binding Chain. Fivo SMS guides customers through all four steps as a complete package, ensuring no step is missed and your SMS goes live fully compliant. Most customers complete full DLT onboarding with Fivo SMS support within 3–5 business days. Full DLT Guide >>
FAQs — SMS Sender ID India
Register Your Sender ID — Get Help from Fivo SMS
📞 Contact Fivo SMS
Sector 63, Noida, UP — 201301
When enquiring, please share:
- Your proposed 6-character Sender ID
- SMS category needed (Transactional / Promotional)
- Your DLT PE registration status
- Monthly SMS volume estimate
Register Your SMS Sender ID with Fivo SMS
Get your custom 6-character Sender ID approved on DLT and start sending branded, TRAI-compliant bulk SMS — Transactional, Promotional, OTP — across all Indian telecom networks.
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