WhatsApp OTP & Authentication Messages: Cheaper, Faster Than SMS
Login and checkout drop-offs are often an OTP problem, not a product problem. WhatsApp authentication templates give faster delivery, a tappable copy-code button and a sender the customer recognises.
How authentication templates work
Meta has a dedicated authentication category with a fixed structure: a code, an optional expiry note and a one-tap copy button. You cannot add marketing content to it.
- Fixed body format approved by Meta
- Copy-code or one-tap autofill button
- Short validity messaging to reduce reuse risk
Reliability and fallback
Send over WhatsApp first, and fall back to SMS only if the message is not delivered within a few seconds — that combination gives the best delivery rate at the lowest blended cost.
Cost comparison
Transactional SMS in India carries per-SMS charges plus DLT overhead. WhatsApp authentication messages avoid DLT template registration entirely and often land cheaper at volume, with read receipts you can actually audit.
Security best practices
Never send OTPs to unverified numbers, expire codes in 5-10 minutes, rate-limit requests per number, and log delivery status for every attempt.
FAQ
Questions people ask about this
Short, practical answers.