# 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 utilise 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.
# Getting started
Getting started with SMS OTP is easy: you just need an agreement with Signicat. Technical questions can be addressed to firstname.lastname@example.org.