Abstract
ABSTRACT The aim of the cost system is to determine the cost of production unites (goods and services) which the project is built for it by the cost elements and loaded by the project, The cost system follow a method of analysis either the exhaustive loading style or the micro loading style . The importance of the paper is related to the importance of taxes, such as the income taxes, which is regarded as the most important revenue of the public budget of the nation and the importance of the data of cost. The paper aims at using the method of variables costs in the taxation accountancy which enables to impose the control over the accounts represented by the commissar, so will reduce the chances of the evasion of taxes. While, the problem of the paper is represented through the accounting method, the taxation which is perfected according to account represented by the corporation of taxes, these accounts supposed to provide the real information about the activity practices of the companies. So, the dependence of the tax corporation for the data prepared according to the variables cost theory will reduce the chances of tax evasion which will achieve justice in taxation. It is necessary to follow up the companies which not represent it for its importance as it is appropriate with the accounts brought by the united accounting system as it reflects the actuality of the costs in the companies .
