The article characterizes the transfer pricing in international markets, analyzes the “arm’s length principle” as the main principle of taxation of interdependent companies, the motivation of transfer pricing participants, the main features of the transfer pricing practice, and the system regulating the transfer pricing at the interstate level. Based on analyzing various aspects of information support for the transfer pricing system, it has been proved that the best approach to improving it is to establish a permanent document flow to substantiate the level of transfer prices and to further draw up management, financial and tax reports. The novelty of the study consists in the recommendations on the sequence of actions to form a unified system of document flow, and management and financial accounting that would provide management with the information on all transactions with affiliates.