Major obstacles to securing rational organization of accounting and analytical support system of the enterprise transaction costs management are examined. Organizational and methodological peculiarities of accounting and analysis of economic entities’ transaction costs are defined. Characteristic aspects of official transaction cost reporting in accounting system as a part of administrative, marketing, and other operating expenses are analysed. Exclusively approximate estimate of most kinds of transaction costs is recorded. A significant impact of the amount and structure of transaction costs on the efficiency of managerial decisions regarding further enterprise activity and competitive performance is proved. Certain approaches to accounting and analytical reporting of the enterprise transaction costs are formed. The aim of the article is to investigate basic approaches to and methodological foundation of identifying, accounting, and analysis of economic entities’ transaction costs, as well as their compliance with modern economic realia. The subject of the article consists of the in-depth clarification of content and economic matter of transaction costs under the conditions of modern economy; definition and generalization of chief problems in adaptive accounting of transaction costs management; justification of accounting reporting of transaction costs with due regard to peculiarities of their formalized and unofficial component reporting in accounting system. Methods of studying into theoretical and methodological background of investigation there are general scientific methods of obtaining knowledge (analysis, theoretical generalization, comparison), which were basically applied while studying approaches to the identification, as well as accounting and analytical reporting of transaction costs; methods of systematization – in establishing preconditions and challenges of accounting and analytical reporting of transaction costs; systematic approach – in determining the scheme of transaction costs origin as far as national economic subjects are concerned; statistical methods – used while analysing the rates of transaction costs. The practical significance of the work consists in the investigation of current methodological aspects of identification, as well as accounting and analytical reporting of transaction costs, in order to work out adaptive mechanisms of their pegging, accounting, and analysis under unstable economic conditions, and what is more, analysis of significance of their influence on competitive capacity of enterprises under the conditions of disequilibrium national economy. Value/originality. The originality of the work consists in the practical reinforcement of scientists’ theoretical insights and formulation of improved mechanisms for the identification, accounting, and analysis of transaction costs. The theory of transaction costs introduced by R. Coase and adapted to unstable conditions of the national economic system development has been taken as a basic concept of identification, accounting and analytical reporting of enterprises’ transaction costs.