Deliver OTPs in
Under 3 Seconds
— Guaranteed
India's fastest Transactional & OTP SMS platform — sub-3-second delivery, 99.99% uptime, 24/7 unrestricted sending, and dedicated priority routes for banks, fintechs, e-commerce, and healthcare platforms.
What is Transactional & OTP SMS?
Transactional SMS delivers critical, time-sensitive messages — OTPs, order alerts, payment confirmations, appointment reminders, and security notifications. Unlike promotional SMS, it reaches DND numbers 24/7 with zero delivery restrictions and the highest priority routing available.
- ✓Delivered 24/7 — no time window restrictions like promotional SMS
- ✓Reaches DND-registered numbers — critical for OTP and alerts
- ✓Sub-3 second delivery on priority routes for OTP use cases
- ✓99.99% delivery rate with multi-route intelligent failover
- ✓End-to-end encrypted transmission for sensitive data
- ✓Fully TRAI DLT compliant with pre-approved template support
Built for Speed, Security & Scale
Every feature engineered for mission-critical delivery — because a failed OTP means a lost customer.
Integrate OTP SMS in Minutes
Simple REST API with SDKs for all major languages. Send your first OTP in under 10 lines of code. Full documentation, sandbox environment, and live code examples included.
- ✓RESTful API — works with any language or framework
- ✓SDKs: PHP, Python, Node.js, Java, .NET, Ruby, Go
- ✓Sandbox mode for development & testing — free
- ✓Webhook callbacks for real-time delivery status
- ✓99.9% API uptime SLA with status page monitoring
- ✓Postman collection + OpenAPI 3.0 spec available
How OTP SMS Delivery Works
From API call to phone buzzing — our optimized 4-stage delivery pipeline ensures every OTP lands in under 3 seconds.
Every Critical Alert & Notification
From login OTPs to delivery alerts — transactional SMS powers every customer-facing operation that demands instant, reliable delivery.
Trusted Across Every Critical Industry
Any business handling user authentication, payments, or time-sensitive notifications relies on our transactional SMS infrastructure.
CheapSMS vs Other OTP Providers
Why 1 Lakh+ developers and businesses choose CheapSMS over Twilio, MSG91, Exotel, and other OTP SMS providers.
| Feature | ✦ CheapSMS | Twilio | MSG91 / Exotel |
|---|---|---|---|
| OTP Delivery Speed | <3 seconds guaranteed | 3–8 seconds | 2–5 seconds |
| Transactional SMS Rate | From ₹0.15/SMS | ₹0.55–1.20/SMS | ₹0.20–0.35/SMS |
| DND Number Delivery | ✔ Always enabled | ✔ Yes | ✔ Yes |
| 24/7 Delivery | ✔ No restrictions | ✔ Yes | ✔ Yes |
| Delivery SLA Guarantee | 99.99% with penalty | 99.95% best effort | 99.9% best effort |
| Indian Carrier Direct Connect | ✔ All 4 operators | Via aggregators | ✔ Direct |
| Minimum Top-up | ₹500 only | $20 (~₹1,650) | ₹1,000+ |
| DLT Registration Help | ✔ Full guided | ✘ Self-service | ✔ Partial |
| Voice OTP Fallback | ✔ Built-in | ✔ Separate product | ✔ Add-on |
Transparent OTP SMS Pricing
No hidden charges. No setup fees. Pay per message with automatic volume discounts. Start free with trial credits.
- OTP & Transactional SMS
- Standard priority routes
- Real-time delivery reports
- REST API access
- DLT template management
- DND delivery enabled
- Email & chat support
- Everything in Starter
- Dedicated priority OTP routes
- Sub-3 second delivery SLA
- Real-time delivery webhooks
- Voice OTP fallback built-in
- Advanced API with retry logic
- Dedicated account manager
- 24/7 WhatsApp + phone support
- Everything in Business
- 99.99% uptime SLA with penalty
- Dedicated SMPP connection
- Custom carrier agreements
- On-premise deployment option
- Custom DLT management
- Security audit & compliance docs
- Custom SLA & billing terms
* Prices exclusive of GST. International transactional SMS rates vary. Contact us for enterprise volumes above 1 Crore SMS/month.
Trusted by Developers & Enterprises
Real feedback from fintech founders, banking teams, and e-commerce CTOs who rely on our OTP infrastructure every day.
"We process 2 lakh OTPs daily for our banking app. CheapSMS delivers under 2 seconds consistently. We've had zero delivery SLA breaches in 14 months. Genuinely the most reliable infrastructure we've used."
"Our previous provider had 3–7 second OTP delays causing massive drop-offs at checkout. Since switching to CheapSMS, OTP delivery is consistently under 2 seconds and our checkout completion rate jumped 28%."
"The Voice OTP fallback feature is brilliant. When SMS hits a network issue, voice kicks in automatically. Our authentication success rate is now 99.96%. No other provider offers this level of redundancy at this price."