This qualitative-corpora analysis aimed to analyze and understand the different errors committed by students in writing application letters from selected higher education institutions in Davao del Norte. Also, it aimed to determine the types and frequency of errors they committed. The study utilized the linguistic framework of Ferris’s (2005) Category of Errors. Results show that all four catego-ries of errors are found in the application letters of the students. Specifically, lexical errors are the most common category of errors committed by the students, followed by mechanical errors and morphological errors, while syntactical errors are the least committed error. The study recommended that students should engage more in business writing activities, specifically the appropriate word usage, vocabulary, and certain grammatical concepts. Consequently, students should also focus on the mechanical aspects of business writing, as these aspects are crucial for readability and coherence of ideas. Although morphological and syntactical errors are less seen in the application letters of students, it is still essential to re-educate and equip students with word formation and sentence con-struction skills to master these concepts and further minimize the likelihood of committing these errors. With this, students can pri-marily improve their business writing skills and be better prepared for their professional careers.