This document is a final stage report for a project titled “An SMS(Short Message Service) application to prevent Sender ID Spoofing.” Sender spoofing is a technique that can easily replace the Sender ID with alphanumeric text. This SMS application is developed by Android Studio, Firebase Realtime Database and Room database. It aims to identify the user of this application through the pre-established secret that is bound with the incoming messages. When a user sends an SMS message to a recipient, this SMS message will be sent through the SMS channel, but the secret for authentication will be stored in an online Database. After the authentication, the authentication results will be stored in the recipient’s mobile device, and the result will be displayed to the recipient. Through this SMS application, the user can quickly check if the incoming message is from the user or not.