The author of this report has created a Web-based invoice system and CRM at therequest of the company Webhouse.se. The purpose of the System is to makeeveryday tasks in the company easier. The system also needed to prevent mistakesand errors by managing orders and invoices.The system has been created with the company’s requests in focus. During thedevelopment of the system information security and interaction design have beenimportant aspects that have been taken into consideration.The system has been created using techniques such as PHP and MYSQL. Theinterface of the system has been created using HTML and CSS. During thedevelopment the student used different tools and software to aid the process.This work resulted in a system that supports the needs of Webhouse.se bymanaging invoices and making sure that clients get an invoice for the services theyhave bought.The process of developing the system has increased the knowledge of the studentand helped gaining valuable experience. It also helped the student to test his knowledge after three years of studies.