


And the concept of OTP itself is not phishing resistant. While this post discusses SMS OTP form best practices, be aware that SMS OTP is not the most secure method of authentication by itself because phone numbers can be recycled and sometimes hijacked.

This post explains best practices to build an SMS OTP form for the above use cases. SMS OTP is commonly used for that purpose. Payment confirmation In payment systems, some banks or credit card issuers request additional authentication from the payer for security reasons.Sending an email to their registered email address or an SMS OTP to their phone number are common account recovery methods. When a user loses access to their account, there needs to be a way to recover it. Sometimes it's combined with a PIN to constitute a two-factor authentication. In such services, users can enter their phone number and the OTP received via SMS to prove their identity. Some services use a phone number as the user's primary identifier. In addition to username and password, SMS OTP can be used as a strong signal that the account is owned by the person who received the SMS OTP. Asking a user to provide the OTP (one time password) delivered via SMS is a common way to confirm a user's phone number.
