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🔐 OTP SMS Service

Best OTP SMS Service
Provider in India

Deliver One-Time Passwords via SMS, WhatsApp & RCS in under 3 seconds. 99.9% uptime, DLT compliant, REST API ready — trusted by 5,000+ businesses across India.

Sign Up Now — It's Free ⚡ Talk to Sales
2–3s
Average OTP Delivery Time
99.9%
SMS Delivery Rate
5,000+
Businesses Trust Nesark
24×7
API Uptime & Monitoring

OTP Delivery Channels

💬
SMS OTP
All operators · DLT compliant
📱
WhatsApp OTP
Official WABA · Rich delivery
✨
RCS OTP
Next-gen · Verified sender
Multi-Channel OTP

See How OTP Looks on Every Channel

Click any channel below to see exactly what your users receive — and choose the best fit for your product.

9:41
▐▐▐ ◀ ●
Messages · NESARK
Your OTP is 847291.
Valid for 10 min.
Do not share.
-Nesark
9:41 AM ✓
Channel 1 of 3

SMS OTP

Widest reach in India — works on every mobile phone without internet. Delivered in 2–3 seconds via priority transactional route, bypassing DND restrictions.

✓
Works without internet
Reaches all mobile users across India
✓
DLT compliant · Bypasses DND
Transactional route — 24×7 delivery
✓
Starting at ₹0.17/SMS
All Indian operators, no expiry on credits
Why Choose Nesark

Everything You Need in an OTP Service

Built for speed, reliability and compliance — so you can focus on your product.

2–3 Second Delivery
OTPs reach your users within 2–3 seconds on average. Priority routing ensures your OTPs never queue behind promotional messages.
DLT Compliant
Fully compliant with TRAI's DLT regulations. All OTP templates are pre-registered as Transactional — zero delivery blocks from operators.
Simple REST API
Integrate in minutes with our clean REST API. Available SDKs for PHP, Python, Node.js, Java and more. Detailed docs at developers.aoc-portal.com.
99.9% Delivery Rate
Industry-leading delivery rates with multi-operator routing. If primary route fails, automatic fallback ensures your OTP always gets through.
Real-Time Delivery Reports
Track every OTP — delivered, failed or pending — in real time via dashboard or webhook callbacks to your server.
24×7 Uptime & Support
Our infrastructure runs round the clock with dedicated monitoring. Support team available via WhatsApp, email and phone for any issue.
Use Cases

Where Businesses Use Nesark OTP

OTP verification is critical across industries. Nesark powers them all.

🛒
E-Commerce & Retail
Verify user login, new account signup, order confirmation, and payment authentication on your shopping platform.
🏦
BFSI & Fintech
Secure fund transfers, mobile banking logins, insurance policy activation and KYC verification with instant OTP delivery.
🏥
Healthcare & Telemedicine
Verify patient identity, doctor login, prescription access and appointment booking portals securely.
🎓
EdTech & eLearning
Authenticate students for exam portals, course access, certificate downloads and parent login verification.
🚗
Mobility & Logistics
Verify driver and customer logins for cab, delivery and logistics platforms. Confirm OTP on delivery and pickup.
🏢
SaaS & Enterprise Apps
Add two-factor authentication (2FA) to your SaaS product, CRM, ERP or internal enterprise applications.
Developer Friendly

Integrate OTP API in Minutes

Our REST API is clean, well-documented and works with any language or framework. A single POST request is all it takes to send an OTP to any Indian mobile number.

REST API with JSON response
PHP, Python, Node.js, Java SDKs available
Webhook support for delivery callbacks
Sandbox environment for testing
View API Documentation →
// Request { "sender": "NESARK", "to": "91XXXXXXXXXX", "text": "Your OTP is {#var#}. Valid for 10 min. -Nesark", "type": "TRANS" } // Response { "id": "58d63c02-XXXX-XXXX-XXXX", "totalCount": 1, "message": "Message Sent Successfully!", "error": null }
How It Works

OTP Delivery in 4 Simple Steps

From API call to OTP in user's inbox — the entire flow takes under 3 seconds.

1
User Triggers Action
User clicks login, signup or payment — your app calls the Nesark OTP API
2
API Sends Request
Your server sends a POST request with phone number and OTP text to Nesark API
3
OTP Delivered Instantly
Nesark routes through priority channels — OTP reaches user in 2–3 seconds
4
User Verified
User enters OTP — your app verifies and completes the secure action
FAQ

Common Questions

An OTP SMS service allows businesses to send One-Time Passwords to users' mobile numbers via SMS for authentication purposes. It is used for login verification, payment confirmation, account signup, and two-factor authentication (2FA) across apps and websites.
Yes. As per TRAI regulations, all SMS senders in India must be registered on the DLT platform. Your entity, sender ID (header) and OTP template must all be registered. Nesark's team assists with the entire DLT registration process free of charge.
Nesark delivers OTPs in 2–3 seconds on average. OTP/Transactional SMS is routed through priority channels that are separate from promotional traffic, ensuring your users receive their OTP without any delay even during peak hours.
Yes. After signing up, Nesark provides free trial credits so you can test the API, check delivery speed and verify integration before committing to a recharge. No credit card is required to sign up.
Transactional SMS (used for OTPs) is sent 24×7, bypasses DND restrictions and is delivered within seconds via priority routes. Promotional SMS is used for marketing, is blocked on DND numbers and can only be sent between 10AM–9PM. OTPs must always use the Transactional route.
No. Credits purchased on Nesark do not expire. You can use them at any time — whether you send 100 OTPs today or 1,00,000 next month, your balance remains valid.

Start Sending OTPs Instantly
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Join 5,000+ businesses using Nesark for fast, reliable OTP delivery. Free trial credits on signup. No setup fee. No contracts.

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