WhatsApp is now a more cost effective channel than SMS to send One-Time-Passcodes (OTPs) in many parts of the world. Check out our Verify WhatsApp API to send OTPs. This purpose-built API intelligently orchestrates OTP delivery between WhatsApp, SMS, RCS and other channels to maximize conversion and reduce cost. In a single phone number verification session, the same OTP code that's generated by Verify is sent across all channels, simplifying code validation.