98%
Open Rate
99.2%
Delivery Rate
< 3s
Avg. Latency
14,821
Sent (today)
14,783
Delivered
38
Failed
2.1s
Avg. Latency
Real-Time Delivery Log
Sample OTP Message
No data connection. No installed app. No notification permission. No algorithm deciding whether to show the message. SMS is delivered to the device's native inbox - where 98% of messages are opened within 3 minutes of receipt. For time-critical communications - OTPs, payment alerts, appointment reminders, fraud warnings - SMS is the only channel that reaches everyone, every time, regardless of their digital environment.
Transactional SMS is not marketing. It is infrastructure. An OTP that takes 11 seconds to arrive on a 30-second validity timer is not a messaging problem - it is a business failure. An appointment confirmation that goes to email is not a communication - it is a hope. Transactional SMS is the channel that delivers when the outcome depends on delivery.
OTP & Authentication
Critical - sub-3s delivery
One-time passwords, login verification codes, transaction PINs, and 2-factor authentication codes are delivered via a dedicated OTP route - optimised for sub-3-second delivery with operator-level priority queuing and automatic retry logic.
Your OTP for login is 847293. Valid for 10 minutes. Do not share with anyone. -CaseyugTech
Order & Transaction Alerts
High - transactional route
Banking & Financial Alerts
Critical - dedicated route
Appointment & Booking Reminders
Medium - transactional route
Logistics & Delivery Updates
High - transactional route
System & Service Alerts
Critical - instant delivery
Five communication channels are compared below across the four metrics that determine whether a time-critical business message actually reaches the customer and produces the intended action.
| Channel | Open Rate | Delivery Rate | Delivery Time | Needs Internet | Needs App |
|---|---|---|---|---|---|
Transactional SMS ← Best for critical comms | 98% | 99.2% | < 3s | ||
22% | 85% | 1–120 min | |||
Push Notification | 7% | 60% | < 30s | ||
WhatsApp Business | 98% | 95% | < 10s | ||
In-App Notification | 4% | 40% | < 5s |
Key insight: SMS is the only communication channel that works without internet, without an app, and without notification permission - making it uniquely reliable for time-critical transactional messages where delivery failure has a direct business cost.
PaySwift - OTP SMS Infrastructure for 2.4M Monthly Authentications
OTP delivery at financial transaction scale is not a messaging problem - it is an infrastructure problem. The previous SMS provider was routing PaySwift's OTP traffic through a shared transactional pool that also carried lower-priority notification traffic. During peak hours (10AM–2PM and 8PM–11PM), OTP delivery latency was spiking to 14–22 seconds - well beyond the 30-second OTP validity window that PaySwift had set as a security measure. Users were entering expired OTPs, failing authentication, and abandoning transactions.
A dedicated OTP route was provisioned through a Tier-1 telecom aggregator with direct operator connectivity - bypassing the shared pool entirely. Automatic retry logic was configured with a 2-second interval and a maximum of 3 attempts before an escalation alert. DLT registration was completed for PaySwift's OTP template across all 5 operators. A delivery receipt dashboard was integrated with PaySwift's internal monitoring system - generating an automated alert when any operator's OTP delivery latency exceeded 5 seconds for 3 consecutive messages.
Outcomes
2.1s
Avg. OTP delivery - from 11.4s
99.7%
Delivery success rate
−91%
Support tickets - OTP not received
6 days
Infrastructure live
Gateway & Tools
"11 seconds to deliver an OTP that expires in 30 seconds is not a delivery service - it is a 37% failure window. We didn't know how bad it was until Caseyug showed us the delivery time distribution in the analytics. The dedicated OTP route brought it to 2.1 seconds. Transaction abandonment dropped immediately. The 2,400 support tickets per month dropped to 214. The infrastructure change paid for itself in the first week."
Vikram Iyer
CTO, PaySwift Fintech
01
Every message type the business needs to send is documented - OTP, order, reminder, alert - with volume estimates, timing requirements, personalisation needs, and the triggering system or event for each.
02
Entity, sender header, and all required message templates are registered on the DLT platform - with document preparation, submission, and approval follow-up managed entirely.
03
The optimal SMS route is configured for each use case - dedicated OTP route for authentication, transactional route for notifications, with operator-specific routing rules and fallback paths.
04
The SMS gateway API is integrated with the client's sending system - CRM, e-commerce platform, HMS, or custom application - with webhook delivery receipts configured for real-time status tracking.
05
Every message type is tested end-to-end across all major operators before go-live - verifying delivery, personalisation variable substitution, template matching, and delivery receipt capture.
SMS is routed through Tier-1 aggregators with direct telecom operator connections - not through resellers with third-party routing chains that add latency and failure points between the message and the recipient.
Every DLT requirement - entity registration, sender header approval, template registration, and operator mapping - is managed entirely, including document preparation, submission, and follow-up with the DLT platform.
Every SMS infrastructure is designed and operated within TRAI's Telecom Commercial Communications Customer Preference Regulations - ensuring no regulatory risk to the client's business from non-compliant messaging.
Delivery receipt dashboards are configured for every client - showing per-operator delivery rates, latency distributions, and failure reasons in real time, not in end-of-month reports.
Every transactional SMS is configured with automatic retry logic and fallback routing - if the primary operator route is congested or the message fails, a secondary path is attempted without manual intervention.
SMS is triggered programmatically from the client's existing CRM, e-commerce platform, hospital management system, or custom application - no manual sending, no CSV uploads, no human intervention for transactional messages.
Since February 2021, TRAI requires every business sending SMS in India to complete DLT registration - entity, sender header, and message template. The six steps below document the complete registration pathway, what each step requires, and what happens to SMS sent without each element.
What This Step Involves
DLT (Distributed Ledger Technology) registration is a mandatory requirement introduced by TRAI (Telecom Regulatory Authority of India) in 2021 for all entities sending commercial SMS in India. Every business that sends SMS messages - transactional or promotional - must register on one of the approved DLT platforms operated by telecom operators before any SMS can be delivered.
⚠ What Happens Without This
SMS messages sent without DLT registration are blocked at the operator level and never delivered to the recipient. Since February 2021, unregistered SMS traffic has been systematically rejected by all major Indian telecom operators - Airtel, Jio, Vodafone-Idea, and BSNL.
DLT registration is managed entirely - entity documentation preparation, platform submission, template writing, approval follow-up, and operator mapping - as part of every transactional SMS engagement. Zero DLT rejections have been recorded across all client accounts.
A free transactional SMS consultation is available. Your use cases, message volume, DLT registration status, and integration requirements will be reviewed - and a recommended infrastructure plan delivered within 24 hours.
Free · No obligation · DLT registration managed · TRAI compliant · 24-hour response
