What is OTP Verification SMS?

A transactional text message that delivers a unique one-time code to verify a user's identity or authorize a specific action during authentication.

OTP Verification SMS is the most common form of mobile-based identity verification used in digital applications. When a user attempts to log in, register, reset a password, or complete a financial transaction, the server generates a unique OTP—typically 4–8 digits—and sends it to the user's registered mobile number. The user enters the OTP in the application to prove they have access to that phone number, adding a critical layer of security beyond just a password. OTP SMS is classified as transactional and exempt from DND restrictions. The verification system must validate the OTP within the expiry window and invalidate it after a single use. BhashSMS offers dedicated OTP routes with intelligent failover to multiple operators for maximum delivery reliability.