OTP Verification API and OTP SMS API
Verify phone numbers and secure logins with OTP SMS on dedicated transactional routes. Add WhatsApp authentication templates as a second channel, with one simple API.
- 24x7OTP delivery, DND too
- DLTTemplate help
- APIHTTP + SMPP
Phone number verification and two-factor authentication
Where businesses use our OTP API.
Phone number verification API
Confirm a user owns the mobile number at sign-up.
Two factor authentication SMS
Add a second step to logins and sensitive actions.
User authentication API
Passwordless login with a one-time code.
OTP SMS for banking
Payment, beneficiary and card OTPs on transactional routes.
OTP API for fintech
KYC, loan and wallet OTPs with fast delivery.
WhatsApp OTP
Authentication templates on the WhatsApp Business API, with SMS as backup.
How to send OTP SMS that arrive fast
Register an OTP template on DLT with the code as a {#var#} near the start, for example "{#var#} is your OTP to log in to BRAND". Use a transactional header, keep the message short, and set an expiry time. Never put the OTP in a link.
Use our OTP SMS templates, check them with the DLT template checker and read the OTP message format guide.
Why businesses choose us
Since 2016, trusted by 15,000+ businesses.
DLT help included
Our team helps with entity, header (sender ID) and template registration.
Direct operator routes
Promotional, transactional and OTP SMS on Airtel, Vi, BSNL and Jio routes.
Live delivery reports
See the delivery status of every message in real time.
HTTP API and SMPP
Developer-friendly SMS API with code samples and SMPP for high volumes.
More than SMS
WhatsApp Business API, RCS, voice, IVR, missed call and email on one account.
Human support
Help on phone, WhatsApp and email, Monday to Saturday.
Frequently asked questions
What is an OTP verification API?
An OTP verification API lets your app send a one-time password to a mobile number by SMS or WhatsApp with one HTTP request, so you can verify the user.
Do OTP SMS reach DND numbers?
Yes. OTPs go on the transactional route with a DLT-approved template, so they reach DND numbers at any time.
Can I send OTP on WhatsApp?
Yes. WhatsApp authentication templates can carry OTPs, and you can use SMS as a backup channel.
Do you generate and check the OTP?
Your application generates and checks the code; our API delivers it by SMS or WhatsApp.
How much does OTP SMS cost?
It depends on volume. Contact our team for a quote.
Ready to get started?
Tell us what you want to send and how many messages a month. Our team will set up a free demo.