WhatsApp OTP vs SMS OTP: Which Is Better for Your Business?

One-time passwords (OTPs) protect logins, payments and sign-ups. Choosing the right channel affects both cost and conversion.

SMS OTP

• Works on every phone, no app required
• Universal reach — ideal for first-time users
• Priced per message

WhatsApp OTP

• Delivered inside WhatsApp, so it feels native and stays in the chat
• Often cheaper per authentication message than SMS in many markets
• Requires the user to have WhatsApp installed (the vast majority do)

The smart approach

Many businesses use both: WhatsApp first for users who have it, with automatic SMS fallback for everyone else. iSend supports multi-channel OTP delivery with fallback built in, so you never lose a sign-up to a failed message.