In serving mail orders (request letter making), the UNS Informatics Engineering D3 secretariat still uses manual methods, namely students and lecturers who want to make a letter must come to the secretariat and fill out the data related to the manual ordering in the book provided. Then the secretariat officer will make the requested letter, and take care of signing and authorizing the letter. This method is certainly less practical and takes a long time. The risk of data loss or data filling errors is also unavoidable. What is more, there is no computer-based system that supports managing mail orders at the study program level. Making this information system uses the waterfall method. The steps of this method are data collection, making system requirements analysis, database design, implementation, and testing. System implementation utilizes MySQL as its database, PHP programming language and codeigniter framework. The resulting system is a web-based mail order information system that is able to handle the mail order transaction process until the letter is printed.