# SMS OTP
# About SMS OTP
Signicat's SMS OTP is a simple identification method based on one-time passwords on the SMS channel. A typical scenario may be this:
- A user accesses a service on a merchant that requires some sort of identification.
- A merchant sends an SMS with an OTP code to the user.
- The user types in the recently received code in the merchant's application.
- The merchant receives the user's telephone number in the response from Signicat.
Although this method alone does not provide adequate security, from a technical standpoint there is nothing that prevents a merchant from using SMS OTP as a standalone authentication method. However, the usual and recommended use case is to use SMS OTP boost an existing login process. SMS OTP, integrated with any username/ password login solution, will form a two-factor authentication method.
# Product information
Signicat SMS OTP can be integrated into your application with minimal effort. The technical integration with the SMS OTP service is identical with all other ID solutions that Signicat supports. There are a number of configuration possibilities for the SMS OTP method, including:
- Possibility for the user to change the mobile phone number before entering the OTP code.
- The length of the OTP codes, downward limited to 4, with no upper limit.
- Which country codes the SMS OTP method is valid for.
# Flow diagram
# How to get started with SMS OTP
Getting started with SMS OTP is easy: you just need an agreement with Signicat. If you have any further questions, contact us at firstname.lastname@example.org.