Financial Reporting by a Shared Ledger Ivars Blums a,1 and Hans Weigand b a SIA ODO, Riga, Latvia. b University of Tilburg, The Netherlands. Abstract. Among models and information about economic phenomena which help to understand how enterprises produce value, Accounting and Financial Reporting still play a leading and regulative role. The regulative role is established by enforceable International Financial Reporting Standards (IFRS). Ontology engineering methods, which have proven to cope with difficult standardization issues, are seldom used in developing the abovementioned standards. Furthermore, the standard setting should more increasingly account for the influence of advanced information technologies for capturing and reporting financial information, such as [blockchain-based] shared ledgers and data analytics. This paper proposes an initial version of the Core Ontology of Financial Reporting Information Systems for a Shared Ledger Environment (COFRIS) grounded on the Unified Foundational Ontology (UFO) network, and a preliminary analysis of the IFRS. Keywords. UFO, REA, IASB, IFRS, COFRIS, Shared Ledger 1. Introduction Ontology engineering methods, which have proven to cope with difficult standardization issues [14], are seldom used in developing standards of international financial reporting (IFRS). Consistency, completeness and clarity of recent editions of Conceptual Framework (CF) for Financial Reporting (FR) [1] and reworked standards [2] by the International Accounting Standards Board (IASB) still need to be improved [6]. We see the following areas of improvement of this framework and standards: • usage of the ontology engineering tools for standard setting, grounding on upper level ontologies; • elimination of the repetitions and inconsistencies among IFRS standards; • elimination of the inconsistencies with other enterprise standards and enterprise ontologies; • generalization of the conceptualization of economic contracts and their progression events [12]; • accounting of the impact of modern information technologies, such as data analytics and shared ledger [11]. Our research attempts to contribute to these improvements by using and extending the general patterns of upper ontologies and by extracting patterns common to all standards. These patterns facilitate the reuse, understanding and precision of IFRS standards and their accompanying documents, which now comprise thousands of pages. The main contribution of this paper is an initial version of the Core Ontology of Financial Reporting Information Systems for a Shared Ledger Environment (COFRIS) 1 Corresponding Author, Ivars Blums; E-mail: Ivars.Blums@odo.lv.