Connect Your OTP Channels Through One API
Send and verify OTPs across SMS, WhatsApp, Viber, and RCS, with automatic routing through the lowest-cost eligible channel and fallback when delivery isn't confirmed.
Trusted by global companies
Choose the OTP Channels That Fit Your Markets
Give your application multiple ways to reach users, with channel selection based on destination pricing, completed sender setup, and recipient eligibility.
SMS
Deliver verification codes to mobile numbers without requiring a messaging app, and use SMS as a fallback when it is the next eligible route.
Explore SMS OTP API →Send authentication codes through your connected WhatsApp Business Account using approved authentication templates.
Explore WhatsApp OTP API →Viber
Reach Viber users in supported markets through an approved business sender.
Explore Viber OTP API →RCS
Deliver verification codes through a branded RCS business sender to recipients with supported devices and carriers.
Explore RCS OTP API →Let SecondFactor Select the Delivery Route
Our Price Intelligence Engine evaluates your eligible channels for each request, so your team doesn't have to maintain channel selection and fallback logic.
1. Check Available Channels
Identify which channels are enabled for your account and eligible for the destination and recipient.
2. Select the Lowest-Cost Option
Rank eligible channels by price and attempt delivery through the lowest-cost route.
3. Fall Back Automatically
Try the next eligible channel if delivery isn't confirmed within eight seconds.
Add Channels Without Rebuilding Your Integration
Use the same /otp/send and /otp/verify endpoints as you connect additional channels, with sender and template setup managed through SecondFactor.
Complete Channel Setup
Register the senders and connect the business accounts required for your selected channels.
Manage Authentication Templates
Create and submit OTP templates with content that meets each channel's requirements.
Review Delivery in One Dashboard
Check which channel handled each request, whether delivery succeeded, and what it cost.
Review OTP Pricing for Your Destination Markets
Check available rates or talk to our team about your expected volume and channel requirements.
Connecting more channels gives the routing engine additional options where those channels are eligible and offer lower delivery costs.
Frequently Asked Questions
Channel setup questions? Write to support@secondfactor.ai.
Which OTP Channels Does SecondFactor Support?+
SecondFactor supports OTP delivery through SMS, WhatsApp, Viber, and RCS. Availability depends on the destination, recipient capabilities, and completed channel setup.
Do I Need to Connect All Four Channels?+
You can start with the channels you need and add others later. Routing and fallback use only the channels enabled and eligible for your requests.
Do I Need a Separate Integration for Each Channel?+
Your application uses one SecondFactor API for sending and verifying OTPs. Each channel may require its own business account, sender registration, or template approval.
Which Channel Is the Cheapest?+
The lowest-cost option depends on the destination and applicable rates. SecondFactor evaluates eligible channels for each request rather than always choosing the same channel.
Will Enabling More Channels Always Reduce My Costs?+
Additional channels can provide lower-cost options, but savings depend on their pricing and eligibility for your traffic. A connected channel may not be available for every recipient.
What Happens if the First Channel Doesn't Deliver?+
If delivery isn't confirmed within eight seconds, SecondFactor tries the next eligible channel. Fallback requires another channel to be enabled and available for that request.
Can I Use the Same Message Across All Channels?+
You can manage templates together, but the message content must follow each channel's rules. WhatsApp authentication templates, for example, use prescribed wording and supported configuration options.
How Can I See Which Channel Was Used?+
Your OTP logs show the delivery channel, destination, status, and cost of each request.
Start Building Your OTP Integration
Create an account to explore SecondFactor, or talk to our team about the channels and setup requirements for your application.