What Is SMS OTP and How Does It Work?

SMS OTP sends a one-time code by text to verify users. This article explains what SMS OTP is, how the send-and-verify flow works and why businesses use it.

SMS OTP is a one-time password sent by text message to verify a user during sign-up, login or payment. Because each code is used once and expires quickly, it sharply reduces the risk of relying on a static password alone.

The send-and-verify flow

1. The user enters a phone number and requests a code.
2. The server generates a code, stores it with an expiry, and sends it via an SMS provider.
3. The user receives the text and enters the code while it is valid.
4. The server checks the code; if correct and unexpired, it proceeds.

Why businesses use SMS OTP

• Reach: works on any phone, no internet required.
• Familiarity: users already know how to enter a code.
• Fast to deploy through a provider API.

SMS OTP wins on reach: almost every customer can receive a text.

Waebox provides SMS OTP

Waebox Media provides SMS OTP with a simple API and high delivery rates. Contact us for API documentation.