The main goal of cost accounting is to achieve efficiency, i.e. to achieve an optimal relationship between costs and results. Today, it is increasingly difficult to achieve the greatest possible long-term benefit from the cost incurred, i.e. to achieve the goal with the lowest possible costs. In every company, cost management deals with the process of finding the right project and executing the project in the right way. This includes activities such as planning, evaluation, budgeting, financing, management, control and comparative costs so that the project can be completed on time and the approved budget and project performance can be improved on time. Resource planning is the process of determining future resource needs for an organization or scope of work. This includes assessing and planning the use of the physical, human, financial and information resources needed to complete the work activities and their tasks. This paper will determine the specifics of cost accounting of companies on the example of the company Fiducia d.o.o. whose main activity is the provision of bookkeeping services. The aim of this paper is to identify the specifics of accounting monitoring, cost accounting and cost management for bookkeeping services. Therefore, their accounting records, documentation and management method will be presented on a practical example, using appropriate methods. At the end of the work it will be determined that the company Fiducia d.o.o. implements all of the above in accordance with applicable legal regulations and rules.