Secure user authentication with fast SMS and voice OTP delivery
Authenticate users and protect transactions with fast OTP delivery through SMS and voice calls, ensuring secure verification and stronger fraud prevention.
25B+Interactions a year, trusted by the leading brands.
How OTP verification works
Customer initiates verification from your app or website
When a customer clicks the ‘Verify’ button on your website or mobile app, your backend system generates a unique one-time password (OTP) to begin the verification process.
Exotel delivers OTP via SMS or voice call instantly
Exotel fetches the generated OTP from your system and securely sends it to the customer’s registered mobile number through SMS or a voice call for quick verification.
Customer enters OTP and gets verified instantly
The customer enters the received OTP on your website or app to complete the authentication process and instantly verify their phone number or transaction.
Why choose OTP APIs
Reduce costs with scalable OTP APIs
Pay only for what you use and scale OTP delivery easily without overspending.
Deliver OTPs instantly
Send OTP messages within seconds and help users complete verification faster.
Handle high OTP volumes easily
Send thousands of OTP messages simultaneously without managing multiple numbers.
Strengthen user verification
Enable secure OTP authentication and protect user accounts from fraud or misuse.
Business use cases for secure OTP authentication
Two factor authentication security
Add an extra security layer by verifying users with OTP during login.
Prevent spam and fake registrations
Stop fake signups and block spam registrations with OTP verification.
Secure password reset requests
Verify user identity with OTP before allowing password reset actions.
Enable fast passwordless logins
Allow users to log in instantly by verifying identity through OTP.
Verify and reactivate user accounts
Confirm user identity with OTP before reactivating inactive accounts.
Protect sensitive transactions with OTP
Secure payments and transactions by adding OTP-based authentication.
Verify new user registrations instantly
Authenticate phone numbers quickly when users sign up on your platform.
Secure logins and transactions with OTP APIs
Authenticate users instantly with SMS and voice OTP delivery.
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OTP service FAQs
What is an OTP service and how does it help businesses verify users and transactions securely?
An OTP service verifies user identity by sending a one-time password to a registered mobile number through SMS or voice call. The user enters the code on the app or website to complete verification and authenticate the transaction securely.
Why should businesses use OTP verification to secure logins, registrations, and transactions?
OTP verification helps businesses confirm user identity during signups, logins, and transactions. It prevents fraud, reduces fake registrations, and adds an additional security layer without increasing friction for customers.
Through which channels can businesses send OTPs to customers for verification?
OTP services deliver verification codes through SMS messages and automated voice calls. This ensures users receive OTPs even if SMS delivery is delayed, improving reliability for logins, registrations, and secure transactions.
How quickly are OTP messages delivered to customers during authentication or verification processes?
OTP platforms are built for fast delivery so users receive verification codes within seconds. Quick OTP delivery helps customers complete logins, registrations, or payment authentication without delays.
Can OTP services handle large volumes of verification requests from businesses?
Yes, OTP platforms are designed to scale and can handle thousands of OTP requests simultaneously. Businesses can verify large numbers of users without managing multiple numbers or complex communication infrastructure.
How does OTP verification help prevent spam registrations and fake user accounts?
OTP verification ensures that users sign up with valid mobile numbers. By requiring a one-time password during registration, businesses can block fake accounts, reduce spam signups, and maintain cleaner user databases.
Can businesses use OTP verification to enable passwordless login for customers?
Yes, OTP authentication enables passwordless login by verifying users through a one-time password sent to their phone. This removes the need for passwords while keeping the login process secure and convenient.
How can OTP verification help businesses secure payments and online transactions?
OTP verification adds an extra security layer to transactions by requiring users to enter a unique code before completing payments or sensitive actions, ensuring only authorized users can proceed with the transaction.