Types of SMS in India — Promotional, Transactional, OTP & All TRAI DLT Categories Explained for 2026

SMS Types

India's SMS ecosystem is unlike any other in the world. Under TRAI's mandatory DLT (Distributed Ledger Technology) framework, every commercial SMS sent in India falls into one of five legally defined categories — each with its own delivery rules, sender ID format, time restrictions, DND permissions, and pricing. Choosing the wrong SMS type in India does not just affect your campaign performance — it gets your messages blocked at the operator level before they reach a single customer. This 2026 guide explains every type of SMS available to Indian businesses, when and how to use each one, how TRAI DLT classifies them, and exactly how Techto Networks handles all five from one platform.

Why SMS Type Classification Matters in India — The TRAI DLT Framework

Before 2021, Indian businesses could send any commercial SMS through a basic aggregator without template pre-approval. TRAI's DLT mandate changed everything. Today, every SMS you send in India must be:

1. Sent by a DLT-registered Principal Entity (your business)

2. Delivered via a DLT-registered Sender ID (your brand header)

3. Matched to a pre-approved DLT message template

4. Classified under the correct DLT message category

The category classification is where most Indian businesses make their most expensive mistakes. An OTP message incorrectly registered as a promotional template gets blocked. A transactional alert sent on a promotional route reaches only non-DND numbers. A marketing campaign sent as "service implicit" to bypass DND filters triggers TRAI penalties.

Understanding the types of SMS in India is not academic — it is the compliance foundation your business communication is built on.

India's five TRAI DLT SMS categories at a glance:

SMS Category	DLT Code	Delivery Window	DND Exempt?	Sender ID Format	Primary Use
Promotional	P	10 AM – 9 PM only	❌ No	6-digit numeric (e.g., 561788)	Marketing, offers, campaigns
Transactional	T	24/7 — no restriction	✅ Yes	6-char alphanumeric (e.g., TN-BRAND)	Order alerts, bank notifications, confirmations
Service Implicit	SI	24/7 — no restriction	✅ Yes	6-char alphanumeric	OTP, 2FA, existing customer service
Service Explicit	SE	24/7 — no restriction	✅ Yes (consent logged)	6-char alphanumeric	Consent-based service communications
OTP	OTP	24/7 — priority route	✅ Yes	6-char alphanumeric	Authentication codes only

Each category is covered in full detail below.

The 5 Types of SMS in India — Complete Guide for 2026

Type 1: Promotional SMS India

What is Promotional SMS? Promotional SMS is any commercial message that promotes a product, service, offer, event, or brand to a customer. It is the "outbound marketing" category of SMS — your brand reaching out to customers to generate awareness, interest, or purchase action.

TRAI DLT classification: Category P (Promotional)

What Promotional SMS can contain:

• Flash sale announcements: SALE! 40% OFF all electronics today only. Shop: store.in/sale

• New product launches: {BrandName} launches {ProductName}. Be the first to try it: link

• Event invitations: {Name}, you're invited to {EventName} on {Date}. Register: link

• Festive campaign messages: Diwali offer: Get ₹500 cashback on orders above ₹2,000. Use: DIWALI500

• Loyalty programme communications: {Name}, you have {Points} reward points expiring this month. Redeem: link

• Winback campaigns: We miss you! Come back to {AppName} and get {Offer}: link

Key rules for Promotional SMS under TRAI 2026:

• Delivery window strictly enforced: Promotional SMS can only be delivered between 10:00 AM and 9:00 PM IST. Messages sent outside this window are not queued for later — they are permanently dropped at the DLT scrubbing layer.

• DND restriction: Promotional SMS can only reach numbers that are not registered on the DND (Do Not Disturb) list. As of 2026, approximately 28 crore Indian mobile numbers are DND-registered — any promotional SMS to these numbers is blocked.

• Exception — Digital Consent Acquisition (DCA): If a customer has given explicit, TRAI-logged digital consent to your brand for promotional communication, their DND registration is overridden for your sender specifically. This requires the DCA process via the DLT Consent Register.

• Sender ID format: 6-digit numeric sender ID (e.g., 561788, 240098). You cannot use a brand name in your sender ID for promotional SMS.

• Template pre-approval mandatory: Every promotional message template must be submitted to and approved by your registered DLT operator portal before the first send.

Promotional SMS pricing at Techto Networks: Starting at ₹0.14/SMS (Starter plan), ₹0.12/SMS (Growth plan), ₹0.10/SMS (Enterprise plan) — DLT charges fully included, credits never expire.

Who uses Promotional SMS: Retail brands, e-commerce platforms, restaurants, real estate developers, event companies, EdTech platforms, hospitality businesses, and any organisation conducting outbound marketing campaigns.

Type 2: Transactional SMS India

What is Transactional SMS? Transactional SMS carries information that a customer has specifically requested or is entitled to receive as part of an existing relationship with your business. It is not marketing — it is service communication. Order confirmations, appointment reminders, account alerts, booking details, delivery updates — all transactional.

TRAI DLT classification: Category T (Transactional)

What Transactional SMS can contain:

• Order confirmation: Order #ORD-48271 confirmed! Delivery by {Date}. Track: link

• Appointment reminder: Your appointment with Dr. {Name} is on {Date} at {Time}. Reply YES to confirm.

• Payment received: ₹{Amount} received for Invoice #{InvoiceID}. Receipt: link

• Delivery update: Your order is out for delivery. Expected by {Time}. Agent: {Name}

• Account alert: Your account balance is ₹{Balance}. Last transaction: ₹{Amount} on {Date}.

• Booking confirmation: Booking confirmed at {Hotel} for {CheckIn}. Booking ID: {ID}.

• Subscription renewal: Your {Plan} subscription renews on {Date} for ₹{Amount}. Manage: link

Key rules for Transactional SMS under TRAI 2026:

• 24/7 delivery: No time restrictions. Transactional SMS delivers at midnight on a Sunday exactly as it delivers at noon on a Tuesday.

• DND exempt: Transactional SMS reaches ALL numbers — including DND-registered ones. Your delivery universe is 100% of your contact list, not just the non-DND segment.

• Sender ID format: 6-character alphanumeric sender ID starting with your operator prefix (e.g., TN-BRAND, VM-SHOP, DM-HOSP).

• Content restriction: Transactional templates cannot contain promotional content. A message that blends "Your order is confirmed" with "Use code SHOP20 for your next purchase" gets reclassified as promotional and loses all DND exemption — and its delivery window shrinks to 10 AM–9 PM.

• Template pre-approval mandatory: Submit your transactional templates to the DLT portal. Variable fields (customer name, order ID, amount) are represented as {#var#} in the registered template.

Transactional SMS pricing at Techto Networks: Same pricing as promotional — ₹0.10–₹0.14/SMS depending on plan. No premium surcharge for transactional routing.

Who uses Transactional SMS: E-commerce brands, hospitals, hotels, banks, NBFCs, logistics companies, subscription services, educational institutions, and every business that needs to keep customers informed about their own transactions and bookings.

Type 3: OTP SMS India (Service Implicit — Priority Route)

What is OTP SMS? OTP (One-Time Password) SMS is a specialised subcategory of Service Implicit messaging used exclusively for authentication and verification. It delivers a unique, time-sensitive code that confirms a user's identity before allowing access, completing a transaction, or authorising a change to an account.

TRAI DLT classification: Category SI (Service Implicit) — OTP sub-type, with a dedicated locked-format template

What OTP SMS contains: Every OTP template in India follows a locked format — TRAI does not permit additional content beyond the OTP code, app name, and expiry:

• {OTP} is your one-time password for {AppName}. Valid for {Expiry}. Do not share with anyone.

• Use {OTP} to verify your {AppName} account. This code expires in {Expiry} minutes.

• Banking-specific (RBI mandate): No URLs permitted in banking OTP messages.

Key rules for OTP SMS under TRAI 2026:

• Dedicated priority route: OTP messages travel on a completely separate infrastructure channel — not the same queue as promotional or transactional traffic. This is what enables sub-3-second delivery regardless of campaign traffic elsewhere on the platform.

• Locked template format: Unlike other SMS types, OTP templates cannot have variable structure. The approved template is fixed — only the OTP value and expiry time are variable fields. You cannot add CTAs, links (for banking OTPs under RBI guidelines), or brand promotional content.

• 24/7, all numbers: No time restrictions. Delivers to DND and VIP numbers simultaneously.

• Expiry-aware delivery: OTPs have a natural urgency that requires the delivery infrastructure to be built for speed, not throughput. A 10-second OTP delay at payment checkout causes transaction abandonment at rates of up to 22% per additional second of wait.

• Voice OTP fallback: If SMS delivery fails after configured retries, an automated voice call delivers the OTP as audio. Techto Networks supports voice OTP fallback natively.

OTP SMS delivery benchmarks — Techto Networks India 2026:

Network	Average Delivery	99th Percentile
Jio	1.2 seconds	2.8 seconds
Airtel	1.4 seconds	3.1 seconds
Vodafone Idea	1.7 seconds	3.6 seconds
BSNL	2.1 seconds	4.2 seconds

OTP SMS pricing at Techto Networks: ₹0.14/SMS on Starter, ₹0.12/SMS on Growth, ₹0.10/SMS on Enterprise — all-inclusive, DLT charges included.

Who uses OTP SMS: Every app, website, or platform requiring user authentication — fintech, banking, e-commerce checkout, healthcare portals, gaming apps, SaaS platforms, government services, and any system using two-factor authentication.

Type 4: Service Implicit SMS India

What is Service Implicit SMS? Service Implicit SMS covers all service-related communications with customers who have an implied consent — meaning they have an existing relationship with your business that makes them reasonably expect to receive service-related messages. The "implicit" refers to consent that exists by nature of the customer relationship, not through a formal opt-in process.

TRAI DLT classification: Category SI (Service Implicit)

The distinction between Service Implicit and Transactional: This is where Indian businesses most frequently misclassify their messages. Here is the clearest way to separate the two:

• Transactional (T): Triggered directly by a specific, recent customer action — an order, a booking, a payment, a login attempt

• Service Implicit (SI): Related to a customer's ongoing relationship with your business — subscription updates, account management, policy changes, usage alerts

What Service Implicit SMS can contain:

• Subscription expiry reminder: {Name}, your {Plan} subscription expires in 3 days. Renew to keep uninterrupted access: link

• Usage alert: {Name}, you've used 80% of your monthly data. Upgrade your plan: link

• Policy update notification: Important update to your {ServiceName} terms effective {Date}. Read more: link

• Account anniversary: {Name}, you've been with {BrandName} for {Years} years! As a valued customer: link

• Product update for existing users: {AppName} v2.0 is live! New features for existing users: {UpdateLink}

• Service disruption notification: Scheduled maintenance on {Date} from {Time} to {Time}. Your {Service} will be unavailable during this window.

Key rules for Service Implicit SMS:

• 24/7 delivery — no time restrictions

• DND exempt — reaches all numbers

• Alphanumeric Sender ID — same as transactional

• No promotional content — service implicit messages that include offers, discounts, or CTAs designed primarily to drive a purchase are reclassified as promotional

Type 5: Service Explicit SMS India

What is Service Explicit SMS? Service Explicit SMS is the most powerful — and most strictly governed — category in the Indian SMS framework. It allows businesses to send any category of service communication to customers, including those on DND, provided the customer has given explicit, digitally logged consent via TRAI's DCA (Digital Consent Acquisition) process.

TRAI DLT classification: Category SE (Service Explicit)

How explicit consent works in India:

1. Your business uses TRAI's Digital Consent Acquisition (DCA) facility to request consent from a specific customer for a specific communication purpose

2. The customer receives an OTP-verified consent request

3. The customer actively confirms consent via OTP

4. Consent is recorded on the DLT Consent Register against the customer's mobile number and your sender ID

5. You can now send SE-category messages to that customer — even if they are DND-registered

What Service Explicit SMS enables:

• Targeted promotional messages to DND-registered customers who have opted in

• Highly personalised service communications beyond standard transactional triggers

• Long-term relationship marketing to a verified, consented audience

Who uses Service Explicit SMS: Banks and NBFCs sending targeted financial product offers to existing customers. Insurance companies sending renewal and upsell communications. Premium subscription services maintaining consented marketing communication with their subscriber base. E-commerce platforms sending personalised recommendations to opted-in DND customers.

Key consideration: The DCA consent process adds operational complexity. For most businesses, Service Implicit and Transactional categories cover 95% of legitimate use cases without requiring explicit consent management. Service Explicit is primarily used by large enterprises with sophisticated CRM infrastructure.

The Critical Difference — Promotional vs Transactional vs OTP SMS India

This is the question every Indian business owner and marketing manager searches — and gets wrong most often. Here is the definitive comparison:

Comparison Point	Promotional SMS	Transactional SMS	OTP SMS
Purpose	Marketing, brand awareness, offers	Service alerts, confirmations, reminders	Authentication and verification only
Delivery window	10 AM – 9 PM IST only	24/7, no restriction	24/7, priority route
DND numbers	❌ Blocked	✅ Delivered	✅ Delivered
Sender ID format	6-digit numeric (561788)	6-char alphanumeric (TN-BRAND)	6-char alphanumeric (TN-BRAND)
Template flexibility	Flexible content structure	Fixed + variable fields	Locked format — OTP and expiry only
URLs allowed	✅ Yes	✅ Yes	❌ No (banking) / limited (others)
Trigger	Campaign-based, scheduled	Event-triggered (order, payment, booking)	Real-time user action (login, checkout)
Speed requirement	Low–medium (5–30 seconds acceptable)	Medium (2–10 seconds)	High (under 3 seconds critical)
Route infrastructure	Shared promotional queue	Dedicated transactional queue	Dedicated priority OTP queue
Can include offers/CTAs?	✅ Yes — this is its purpose	❌ No — loses DND exemption	❌ No — template is locked
DLT category code	P	T	SI (OTP sub-type)
Techto Networks pricing	₹0.10–₹0.14/SMS	₹0.10–₹0.14/SMS	₹0.10–₹0.14/SMS

The most expensive classification mistake Indian businesses make: Sending a transactional message on a promotional route — or vice versa. A hospital booking confirmation sent on a promotional route reaches only non-DND patients (missing 28–35% of recipients) and only between 10 AM and 9 PM (missing confirmations for early-morning appointments). The fix: register the booking confirmation template under Category T, use an alphanumeric Sender ID, and route through the transactional channel. Techto Networks classifies and routes automatically based on your DLT template category.

SMS Sender ID Types in India — What the Format Tells You

Every Indian business confused about SMS sender IDs is actually confused about which type of SMS they are sending. The sender ID format is determined entirely by the DLT category — not by your preference:

Numeric Sender ID (Promotional SMS Only)

Format: 6-digit number — e.g., 561788, 240098 Used for: Promotional SMS only Why numeric: TRAI mandated numeric sender IDs for promotional SMS to make it visually clear to recipients that the message is marketing — they cannot be mistaken for a named brand communication Can you choose the number? No — the 6-digit numeric ID is assigned by the DLT portal and operator Example display on phone: From: 561788 — no brand name visible to recipient

Alphanumeric Sender ID (Transactional, OTP, Service SMS)

Format: 6 characters — letters and numbers — e.g., TN-BKNG, VM-HDFC, DM-HOSP Used for: Transactional, OTP, Service Implicit, Service Explicit SMS Structure convention: Operator prefix (2 chars) + hyphen + brand abbreviation (3–4 chars) — e.g., TN- for Techto Networks clients Why alphanumeric: Allows brand identity in the sender field — recipients see your brand name, increasing open rates and reducing the "is this real?" hesitation that anonymous numeric sender IDs create Registration process: Submit your preferred alphanumeric Sender ID via the DLT portal for approval. Techto Networks handles this registration for all clients at no cost. Example display on phone: From: TN-BKNG — brand-identifiable

Critical rule: Using an alphanumeric Sender ID for promotional SMS is a TRAI violation. Using a numeric Sender ID for transactional SMS will cause delivery failures at the operator level because the DLT system validates sender ID format against message category.

TRAI DLT Template Registration — How Each SMS Type Gets Approved

Every SMS type in India requires a pre-approved template on the DLT portal. Here is how the template registration process works for each type:

How DLT Templates Are Structured

DLT templates use {#var#} as the placeholder for variable content at send time. The static (fixed) text of your message is what gets approved — variable values can change per recipient at send time without re-approval.

Promotional template example (Category P):

DLT Template: Get {#var#}% off on all {#var#} at {#var#}. Shop now: {#var#}
At send time: "Get 30% off on all electronics at TechMart. Shop now: techmart.in/sale"

Transactional template example (Category T):

DLT Template: Your order #{#var#} has been confirmed. Delivery by {#var#}. Track: {#var#}
At send time: "Your order #ORD-48271 has been confirmed. Delivery by 18 May. Track: brand.in/track"

OTP template example (Category SI — OTP sub-type):

DLT Template: {#var#} is your OTP for {#var#}. Valid for {#var#} minutes. Do not share.
At send time: "847291 is your OTP for MyApp. Valid for 10 minutes. Do not share."

Common Template Rejection Reasons in 2026

TRAI's DLT portal rejects templates for specific, avoidable reasons. Understanding these before you register saves days of delay:

• Category mismatch: Template content that clearly matches one category submitted under a different one (e.g., a promotional offer submitted as transactional)

• Too many variable fields: Templates where more than 50% of the content is variable raise red flags. The static content must clearly define the message purpose.

• Prohibited content in OTP templates: Any content beyond OTP value, app name, and expiry — including URLs in banking OTP templates (RBI mandate)

• Ambiguous variable context: A {#var#} field immediately following another {#var#} without static text separating them confuses the matching engine

• Missing mandatory elements: Transactional templates must clearly reference a specific transaction or service event; promotional templates must include an opt-out reference

Techto Networks DLT template support: Our compliance team reviews every template before DLT submission, identifies potential rejection reasons, and guides restructuring where needed. All new client templates are submitted on your behalf — no navigating the DLT portal UI yourself.

Which Type of SMS Should Your Business Use? — A Decision Framework

Use this decision tree to determine the correct SMS type for any message you plan to send:

The 5-Question SMS Type Selector

Question 1: Is this message triggered by a customer action that just happened?

• Yes → Likely Transactional (T) or OTP (SI) → Go to Question 2

• No → This is a campaign send → Likely Promotional (P) or Service Explicit (SE)

Question 2: Does the message contain authentication codes (OTP)?

• Yes → OTP (Service Implicit) — use priority route

• No → Transactional (T) — use transactional route → Go to Question 3

Question 3: Does the message promote a product, offer, or incentive — even subtly?

• Yes — even a "use code X for next purchase" at the end → Promotional (P) — remove the offer or split into two messages

• No → Confirm as Transactional (T)

Question 4: Is the customer on DND — and must you reach them?

• This message is pure service communication → Register under SI (Service Implicit) which is DND-exempt

• You want to send them marketing — and they've given explicit consent → Service Explicit (SE)

• You want to send them marketing — and they haven't consented → Cannot legally reach DND numbers. Promotional SMS is blocked for DND subscribers.

Question 5: Does this message serve an existing customer's ongoing service relationship — not a specific triggered event?

• Yes → Service Implicit (SI) — ongoing service relationship communication

• No, it was triggered by an immediate customer action → Transactional (T)

Industry-by-Industry SMS Type Usage — What Category Does Each Sector Use?

E-Commerce and Retail

Message	SMS Type	Why
Flash sale announcement	Promotional (P)	Marketing — promotes an offer
Order confirmed	Transactional (T)	Triggered by purchase action
OTP at checkout payment	OTP (SI)	Authentication code
Delivery update	Transactional (T)	Ongoing service communication
Abandoned cart recovery	Promotional (P)	Marketing re-engagement
Loyalty points update	Service Implicit (SI)	Ongoing service relationship

Banking and Fintech

Message	SMS Type	Why
Transaction alert	Transactional (T)	Triggered by account event — RBI mandated
Login OTP	OTP (SI)	Authentication
Payment OTP	OTP (SI) — No URL (RBI)	Authentication for banking transaction
Credit card offer	Promotional (P)	Marketing — to non-DND customers only
Low balance alert	Service Implicit (SI)	Ongoing account service alert
KYC reminder	Service Implicit (SI)	Ongoing compliance service alert
New product offer to existing customer	Service Explicit (SE)	Requires DCA consent if customer is DND

Healthcare

Message	SMS Type	Why
Appointment confirmation	Transactional (T)	Triggered by booking action
Appointment reminder	Service Implicit (SI)	Ongoing service relationship
Lab result ready	Transactional (T)	Triggered by lab event
Health camp invitation	Promotional (P)	Marketing outreach
Prescription refill reminder	Service Implicit (SI)	Ongoing patient service
OTP for patient portal login	OTP (SI)	Authentication

Education and EdTech

Message	SMS Type	Why
Exam schedule	Transactional (T)	Triggered by academic calendar event
Fee payment receipt	Transactional (T)	Triggered by payment
Fee due reminder	Service Implicit (SI)	Ongoing service relationship
Admission campaign	Promotional (P)	Marketing to new prospects
Result announcement	Transactional (T)	Triggered by result publication
OTP for LMS login	OTP (SI)	Authentication

Logistics and Supply Chain

Message	SMS Type	Why
Shipment dispatch	Transactional (T)	Triggered by dispatch event
Delivery attempt notification	Transactional (T)	Triggered by delivery attempt
Delivery confirmed	Transactional (T)	Triggered by delivery completion
Pickup scheduled	Transactional (T)	Triggered by scheduling action
Promotional offer on freight	Promotional (P)	Marketing
Driver OTP for safe delivery	OTP (SI)	Authentication

How Techto Networks Manages All 5 SMS Types in One Platform

Every SMS type described in this guide is available under one Techto Networks account — one dashboard, one API, one credit balance, and one DLT compliance team.

How Techto Networks handles SMS type routing automatically:

When you create a campaign or send via API, the platform reads the DLT Template ID you provide, checks the registered category for that template (P, T, SI, SE, OTP), and routes the message through the correct infrastructure channel automatically. You do not manually select "promotional route" or "transactional route" — the DLT category drives the routing decision.

This matters because:

• Wrong-route sends are prevented at the platform layer — if you attempt to send an OTP via a template registered as promotional, the API returns a validation error before the message is submitted

• DND scrubbing is applied category-appropriate — promotional sends scrub the DND list at send time; transactional and SI sends bypass scrubbing entirely

• Time-window enforcement — promotional sends scheduled outside 10 AM–9 PM IST are either rejected or queued until the permitted window begins, depending on your campaign settings

What Techto Networks handles for you:

• Entity registration on all 6 DLT operator portals (Jio, Airtel, Vodafone Idea, BSNL, TATA, Videocon)

• Sender ID (Header) registration in the correct format per SMS type

• Template submission and approval for all 5 SMS categories

• Template category classification review before submission — preventing costly rejection

• Ongoing compliance monitoring as TRAI updates DLT rules

• Automatic DND scrubbing for promotional sends

• Route assignment based on DLT template category — zero manual routing decisions needed

Pricing for Each SMS Type in India — 2026 Complete Breakdown

A common misconception: different SMS types cost different amounts from most providers. At Techto Networks, all SMS types are priced identically — we do not charge a premium for OTP routes or transactional classification.

Market pricing benchmark 2026 (per SMS, inclusive of DLT charges):

SMS Type	Market Range (Other Providers)	Techto Networks All Plans
Promotional SMS	₹0.12 – ₹0.25	₹0.10 – ₹0.14
Transactional SMS	₹0.15 – ₹0.22	₹0.10 – ₹0.14
OTP SMS (Priority Route)	₹0.18 – ₹0.30	₹0.10 – ₹0.14
Service Implicit SMS	₹0.13 – ₹0.20	₹0.10 – ₹0.14
Service Explicit SMS	₹0.15 – ₹0.22	₹0.10 – ₹0.14

Techto Networks plan pricing — all SMS types, all inclusive:

Plan	Price/SMS	Volume	What's Included
Starter	₹0.14	Up to 50,000/month	All 5 SMS types, DLT support, delivery reports
Growth	₹0.12	50K–5L/month	All 5 SMS types + API + WhatsApp + priority OTP
Enterprise	₹0.10	5L+/month	All 5 types + dedicated manager + SLA + SMPP

All plans include:

• DLT submission charges fully included (₹0.025/message TRAI fee — in the price, not added later)

• All 5 SMS categories from one account

• Credits that never expire

• Free DLT registration, Sender ID approval, and template submission

What's New in Indian SMS Categories for 2026 — TRAI Updates

The DLT framework is not static. TRAI has made several key changes in 2025–2026 that affect how SMS types are classified and delivered:

Tighter template matching algorithm In 2026, telecom operators have upgraded their real-time template matching engines. The variable content in your messages is now more strictly validated against the registered {#var#} positions. A message where a variable field's content is semantically inconsistent with the template's context (e.g., a product name appearing where an order ID was expected) may trigger a match failure. Techto Networks' pre-send validation catches mismatches before they reach the operator.

Promotional window update: 10 AM start (not 9 AM) A commonly missed update from late 2024: TRAI revised the promotional SMS delivery window from "9 AM–9 PM" to "10 AM–9 PM". Messages scheduled or sent between 9:00 AM and 9:59 AM are now blocked. Techto Networks' promotional scheduler enforces the 10 AM start time automatically.

DCA (Digital Consent Acquisition) expansion TRAI is actively expanding the industries required to use the DCA consent framework for Service Explicit messages. Financial services and healthcare were the primary sectors in 2025. In 2026, the DCA requirement is being extended to education and real estate sectors for certain categories of customer communication. Techto Networks' compliance team monitors these changes and notifies affected clients proactively.

RBI banking OTP URL restriction — strictly enforced in 2026 Since late 2024, RBI's mandate prohibiting clickable URLs in banking OTP messages is being enforced at the operator level — not just as a guideline. OTP templates for banking clients that contain links are blocked at delivery. All Techto Networks banking client OTP templates were updated at the time of the RBI directive.

AI-assisted route optimisation Techto Networks' platform now uses AI-driven real-time route selection for all SMS categories — analysing operator performance data every 60 seconds and routing each message through the highest-performing available path for that operator at that moment. The result is measurably higher delivery rates during peak network congestion periods (festival sales, IPO subscription windows, payment deadlines).

Frequently Asked Questions — Types of SMS in India 2026

Q: What are the types of SMS in India? India has five TRAI DLT-defined SMS categories in 2026: Promotional SMS (Category P) for marketing messages to non-DND numbers between 10 AM and 9 PM; Transactional SMS (Category T) for service alerts and confirmations, delivered 24/7 to all numbers; OTP SMS (Service Implicit — OTP sub-type) for authentication codes on a dedicated priority route; Service Implicit SMS (SI) for ongoing customer relationship communications; and Service Explicit SMS (SE) for messages to DND customers who have given explicit digital consent via TRAI's DCA process.

Q: What is the difference between promotional and transactional SMS in India? Promotional SMS is for marketing — offers, discounts, campaigns — delivered only between 10 AM and 9 PM to non-DND numbers, using a 6-digit numeric sender ID. Transactional SMS is for service communications — order confirmations, appointment reminders, bank alerts — delivered 24/7 to all numbers including DND-registered ones, using a 6-character alphanumeric sender ID. Mixing promotional content into a transactional template causes reclassification to promotional — removing all DND exemption and time-window flexibility.

Q: Can promotional SMS be sent to DND numbers in India? Generally no. Promotional SMS is blocked for all DND-registered numbers — approximately 28 crore numbers in India as of 2026. The only exception is when a DND-registered customer has given explicit digital consent via TRAI's DCA (Digital Consent Acquisition) process, which logs their consent on the DLT Consent Register. Once consent is logged, Service Explicit (SE) category messages can be sent to that number regardless of DND registration.

Q: What is the sender ID format for each SMS type in India? Promotional SMS uses a 6-digit numeric sender ID assigned by the DLT portal — the recipient sees a number, not a brand name. Transactional, OTP, Service Implicit, and Service Explicit SMS all use a 6-character alphanumeric sender ID starting with an operator prefix — for example TN-BRAND or VM-SHOP — which shows your brand name in the recipient's message inbox. Using the wrong format for the wrong category causes delivery failure at the DLT scrubbing layer.

Q: What is the cost of different types of SMS in India in 2026? Market pricing inclusive of DLT charges in 2026: Promotional SMS ₹0.12–₹0.25 per SMS; Transactional SMS ₹0.15–₹0.22 per SMS; OTP SMS ₹0.18–₹0.30 per SMS on priority routes from most providers. Techto Networks charges the same rate for all SMS types — ₹0.14/SMS (Starter), ₹0.12/SMS (Growth), and ₹0.10/SMS (Enterprise) — with DLT charges fully included and credits that never expire.

Q: What is the new promotional SMS window in 2026 — 9 AM or 10 AM? The promotional SMS delivery window in India in 2026 is 10 AM to 9 PM IST. TRAI revised the start time from 9 AM to 10 AM effective late 2024. Messages sent or scheduled between 9:00 AM and 9:59 AM are blocked and dropped permanently at the operator level — they are not queued for delivery at 10 AM. Techto Networks' promotional scheduler automatically enforces the 10 AM start boundary.

Q: What is Service Implicit SMS in India? Service Implicit SMS (Category SI) covers communications with customers who have an implied consent by virtue of their existing relationship with your business. Unlike transactional SMS which is triggered by an immediate customer action (a purchase, a booking), Service Implicit covers ongoing service communications — subscription reminders, usage alerts, account status updates, policy notifications. It delivers 24/7 to all numbers including DND-registered ones, like transactional SMS, because it carries information the customer is reasonably expected to need as part of their existing service.

Q: Do I need separate accounts for different SMS types in India? No — if you use a provider who supports all categories from one account. Techto Networks provides all five TRAI DLT SMS categories (Promotional, Transactional, OTP, Service Implicit, Service Explicit) from one dashboard, one API endpoint, and one credit balance. Route assignment is automatic based on the DLT template category of each message. Managing separate accounts or providers for different SMS types creates billing complexity, DLT coordination overhead, and compliance risk from inconsistent handling.

Q: How does TRAI's DLT system classify my SMS type automatically? It does not — the classification is your responsibility at template registration. When you submit a message template to the DLT portal, you declare its category (P, T, SI, SE, or OTP). The portal validates that the template content is consistent with the declared category. At send time, the operator's gateway cross-references your message against the registered template and category, and routes or blocks it accordingly. Getting the category right at registration is critical — Techto Networks' compliance team reviews every template before submission to prevent misclassification.

Ready to Send Every Type of SMS Your Business Needs — From One Platform?

Understanding the types of SMS in India is the first step. Executing them correctly — with the right DLT category, the right Sender ID, the right route, and the right compliance infrastructure — is where Techto Networks does the heavy lifting for you.

One account. All five SMS types. Every Indian network. One price for all categories. Credits that never expire.

Techto Networks — One Platform for All Types of SMS in India. Promotional. Transactional. OTP. Service. 2026.