Leading OTP SMS Platform for Businesses | Exotel

Use case

Reliable OTP SMS Service

Implement two-factor authentication with SMS.




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cloud telephony - south east asia - exotel
cloud communications

What is an OTP SMS?


OTP SMS or one-time password SMS is used for authentication. The OTP is usually a randomly generated number or an alphanumeric code that is entered into your website or app to verify portal logins, payment confirmations, or service requests for your business. This is part of a mandatory two-factor authentication process to protect your customers’ interactions with businesses.

Why use Exotel’s OTP SMS

Find out why you should use OTP SMS for Business Communication in this video

Why Exotel?

Industry-standard delivery & engagement rates

Our intelligent SMS routes ensure that your business messages get delivered every time, on-time, for instant communication.


TRAI & DLT scrubbing compliance

We’ve made it extremely easy to comply with TRAI guidelines and DLT template scrubbing with resources to help you every step of the way.

Unbeatable prices

We offer the best prices in the market. Show us lower rates and we will match them.

Real-time reports

Know performance levels of your OTP SMS campaigns through metrics like delivery, open and click rates.

Highly flexible

Working on the REST format, our OTP SMS APIs are programmable to work with your enterprise tech stack. 

Simple to implement & use

Our platform’s user-friendly and straightforward interface allows you to set up an SMS campaign in 5 minutes.

Best-in-class security protocols

Our platform is secured end-to-end through robust practices. That means your customer data is completely safe with us.

Unbeatable platform uptimes 

We guarantee best-in-class platform uptimes of 99.94% – this includes operator uptimes

How can businesses use SMS OTP?


To allow your customers secure access to websites like net banking or to allow delivery agents into secured communities, OTP SMS play a crucial role

Transaction Verification

Protect your customers from financial fraud by authenticating transactions of any value.


Safely allow your customers to gain access to portals they were kept out of due to unsuccessful password attempts or any email address or phone number changes.

Account reactivations

Win new business back from the right customers through a secure OTP verification step to restart their services with you.

Shifting away from password logins

Offer a faster, yet safe login experience by considering skipping passwords for OTPs as a real-time authentication process.

How does OTP SMS service work?



Verification request by the customer

Customer clicks on the ‘Verify’ button on your app or website and a unique OTP is generated in your backend system.


Exotel verification

Exotel fetches the generated OTP and sends it to your customer’s registered mobile number through an SMS.


Customer’s number is verified

Your customer enters the unique OTP (sent to him/her via an SMS) in your app or website and gets verified instantly.

Benefits of using OTP SMS


Assured, rapid, 24×7 delivery

With dedicated SMS routes for OTP SMS, messages are not interrupted by any peak in SMS traffic. And an SMS is usually delivered in a few seconds.



An OTP SMS service offers one of the highest cost-benefit ratios when it comes to a reliable, fast, and accurate authentication channel.


Prevent spam

Create a security filter with OTP verification to prevent fake web form or product sign-ups so you only the right requests reach the right teams.


Easy software integrations

Set up campaigns with easy-to-use OTP SMS APIs that connect the SMS software with your enterprise software like an ERP.


Personalise formats

Popular vendors offer easy-to-configure OTP SMS APIs to set up any of the use cases listed here.


Track performance

Gauge deliverability and open rates by pulling reports from the dashboard. Test different strategies to improve results.

Asia’s most innovative companies use Exotel

Asha Satapathy

Exotel’s SMS delivery rate is quick. We have observed an improvement in our customer experience after using Exotel.

Founder & CEO, DocEngage

Raju Pardeshi

We’ve been using Exotel since BookRyde’s first baby step. It has really helped us implement and run SMS solutions seamlessly.

Founder & CEO, BookRyde

Apurv Jain

Exotel helps us in the entire packaging of the SMS reminders channel, thereby leaving the user delighted, satisfied, and retained with Haptik.

Product Manager, Haptik

Praveen Chandran

Our level of efficiency has drastically increased ever since we’ve started using Exotel. It’s increased by at least 3X.

Product Head, Quikr Services, Quikr

How our customers use our SMS Solutions

Automated SMS reminders contributed to 40% of Haptik’s customer retention results

Read More

How Exotel helped Practo revolutionise the way people connect with doctors

Read More

99dotco improved lead attribution by 20% by sending SMS alerts for missed customer calls

Read More


How fast can I set up my account?

Usually, account activation takes 30 minutes. Here are the steps to follow -

1. Sign up for a trial
2. Verify your number and the virtual number assigned to your account
3. Complete your KYC

Once your KYC is verified (usually takes 30-45 minutes), you can start making/receiving calls and sending SMSes from your dashboard. 


Know More

What are the inbound and outbound call charges?

Call charges for inbound and outbound calls are as follows:

For Indian customers
Pricing starts from**
Single-Leg Call Charges (Same Circle) - INR 0.40/min
Single-Leg Call Charges (Other Circle) -INR 0.75/min
**The prices vary based on volumes of calls. Talk to sales for more or sign up and test our free trial for 15 days

For International customers
Pricing varies on the country you want to make or receive calls from. Contact our international sales for pricing details.

Note: To get a correct price estimation based on your volumes and use case, please contact our sales team.


Contact Us

How long does it take to set up a call management software?

A cloud call management software can be set up anywhere between 2 to 3 hours. In fact, we helped Zerodha set up their call management system within 3 hours.

How does pricing work for the voice calls?

Exotel charges voice calls on a per-leg basis:

1. Inbound Calls - An Inbound call is a single-legged call ~ When a call lands on a customer-facing number, Exotel dials an agent number to connect the customer’s call.

2. Outbound calls - An Outbound call is a double-legged call ~ When an agent calls customer, Exotel first dials agent number and then dials the customer number to connect them over a virtual number.

View call pricing here.

Start 15-day trial

Talk to Sales

How is a hosted contact centre software different from a traditional PBX or EPABX?

Compared to a traditional PBX system, the cloud telephony system allows you to pay for what you use, broadly through plans that suit business requirements or scale. Enterprises can talk to us (link below) for custom configurations to help large-scale teams engage better, or to support a host of use cases. All you need to get started with cloud telephony is a computer and internet connection.

Contact our enterprise team

How to choose the best OTP service provider in India?

Choosing a reliable OTP service provider in India is the key to implement a robust authentication system. Below are some of the important factors to consider:

1. Delivery and Latency Rates: Always choose a provider that can assure you of better OTP delivery rates and lower latency rates.​

2. Flexible APIs: If you are implementing an OTP authentication system using APIs, then make sure that your OTP service provider’s APIs are flexible and easy to implement in your backend systems.

3. Data Security: Your customers’ data should be your number one priority. Always choose a provider that is ISO certified and exercises enterprise-grade security practices.

4. Scalability: Always choose a provider that can quickly scale up or down according to your business needs.

5. Customer Service: Choose an OTP service provider that values your time and truly cares about your success. Always ask if you are getting timely support in case you run into problems.

Can I remove my business number from Truecaller's Spam list if I sign up for its Verified Business Caller ID?

The Verified Business Caller ID solution is not a spam removal solution rather is a brand

identity solution to ensure better identification, branding, and context to improve calling efficiency. It also helps prevent identity theft by scammers. The overall aim is to improve customer confidence and not to whitelist spam numbers. Crossing the spam threshold that is visible through an additional spam score tag on incoming call screens doesn't limit all the features offered as part of the solution.


Talk to an expert


What is the UL VNO License and in which circle we have the license?

UL VNO is a Unified License Virtual Network Operator. UL VNO license enables us to offer full fledged telecom services by the network of NSO (Network Service Operator) like Airtel, Tata etc.

We now have an UL VNO license in the Karnataka circle under entity name Veeno Communications Private Limited.


How much does SMS gateway cost?

The charges for SMS gateway is based on your usage. Contact our sales team to know more.


Contact Sales

How to send bulk SMS?

First, integrate the Exotel SMS Gateway with your application stack, following a simple process. Then, SMSes sent right from your website, CRM, ERP, mobile application etc., will then automatically pushed to your customers through the gateway.

Try Exotel’s OTP SMS Solution Free for 7 days



Exhaustive guide on 2 factor authentication

From SMS OTP, to OTP over call, to email OTP, to no OTP at all! We show how 2FA evolved over time.

Find out how Exotel can work for you. Set up a call.

We take away some of the biggest pain points of traditional systems like customer interactions with business.


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