This study proposed an ontological EPA model (Event, Principle and Account) for describing accounting principles using a reusable knowledge component. The essential characteristics of the model include: (1) based on traditional accounting definitions for typical accounts (A) and business events (E), where the ontological properties of A and E can be identified. These characteristics can be further used to create a knowledge hierarchy for both A and E; (2) identifies the element P (accounting principle), which in turn can be used to measure the economic effects of events on accounts; (3) creates a relationship between E–P, which identifies how to adopt suitable principles for classifying events; and (4) the inferential (E–P)–A relationship, which identifies the effect of a classified event on resources (or accounts). Following typical knowledge engineering processes, hierarchical knowledge of accounting principles can be represented, stored and reused. EPA examples are demonstrated using OWL-based ontology. This study claims that the knowledge framework developed in EPAcan provide a basis for full accounting knowledge creation, storage and sharing.