Authentication message
Updated
Quick answer: An authentication message is a WhatsApp template used only to send one-time passwords (OTPs) and verification codes, usually with a copy-code or one-tap button. Meta uses a fixed preset format for these templates, and in India they cost about ₹0.12 per delivered message in 2026.
The WhatsApp template category for one-time passwords.
Businesses use WhatsApp OTPs for sign-up and login because delivery is fast and read rates are high compared with SMS.