Aim of research: grounding of theoretical, organizational and methodic statements as well as development of practical recommendations on accounting improvement under outsourcing. Object of research: accounting process at customer and contractor under outsourcing. Subject of research: theoretical, organizational and methodic bases of accounting under outsourcing. Methods of research: historical, logical, analysis, synthesis, induction, deduction, system approach, logical and gnoseological, statistic, formalization, factor analysis approach, method of analogy. Scientific novelty of results obtained lays in scientific grounding of theoretical and methodic statements and working out practical recommendations on accounting improvement under outsourcing. In the research the following results with scientific novelty have been obtained: for the first time: system and process interpretation of accounting organization under outsourcing, which is referred to as a system of organizational as well as legal actions and as a process, that guarantees the further development of accounting outsourcing as a form of accounting organization for SME's (customers) and type of business activity for external subjects (executors) has been obtained; the issues has been improved as follows: economic and legal bases of responsibility allocation under accounting outsourcing (allocation of rights, duties and responsibilities among clients (customers) and executors at all stages of accounting organization and bookkeeping taking into considering of which the complex of procedures of concluding the contract for rendering accounting outsourcing services, which enables increasing the level of trust among the parties and meeting their interests; documental and staff support of performing duties concerning accounting organization and bookkeeping under outsourcing by client and executor (package of cumulative, reporting documents as well as structural and logical scheme of documents circulation under outsourcing have been offered), which facilitates the increasing operativeness of obtaining accounting information and decreasing of profitability likelihood of arising mutual complaints concerning performance of given services; methodic approaches towards determining costs of accounting outsourcing services grounding on using job-order costing method, which ensures cost specifying considering the detailed allocation of incurred indirect costs and carrying out estimation of profitability of services given; the methodic provision of complex estimation of accounting outsourcing effectiveness, which is presented by qualitative (indicators of informativeness, accuracy of registration, authenticity of generalized summary and risk minimization) and quantitative (accounting outsourcing effectiveness ratio) indicators considering the types of risks, which arise in the process of accounting outsourcing application, for making sound managerial decisions concerning expediency of involving external parties for keeping accounting records; the following issues undergone the further development: determination of factors, which have caused the development of accounting organization forms under market business conditions (extension of organizational and legal forms of activity, change of inquiries of subjects of economic system towards information as well as approaches towards enterprise's management organization with prevailing of economic expediency principle), which enabled to classify accounting organization forms according to enterprise (insourcing, outsourcing) for complex grounding of tendencies and determining of prospectives of accounting outsourcing development; distinguishment of the stages of choosing the external party of keeping accounting records: setting up requirements to accounting organization at an enterprise, making decision concerning using accounting outsourcing, working out criteria of choosing external executor and their estimation, negotiating and determining main issues on collaboration considering groups of criteria worked out (quantitative and qualitative), which makes possible risks minimization of a customer along with avoiding baseless expenditure of financial resources; the system of analytical accounting for costs on organizing and keeping accounting records under outsourcing at the customer's enterprise by developing its levels under computerization and establishment in accounting policy, aimed at receiving information in context of the stages of contractual process required for determining the effectiveness of using accounting outsourcing by a customer. Extent of implementation: research results have been implemented into the practice of LLC MP "TETIJIV AGROINVEST", Auditing Company "MGI Consulting, Ltd.", LLC "Reklamne Djerelo". Some results have been applied in the educational process of Zhytomyr State Technological University while teaching "Accounting Organization", "Financial Accounting I", as well as have been used in activity of the scientific studios "Chief Accountant" and "Auditor".