EN
It is common for the majority of income tax systems all over the world that the cost of debt financ- ing lowers the taxable income while financing with equity is not treated similarly. The question raised in the article is connected with the way the cost of equity financing can be calculated for tax purposes. The aim of the paper is to identify and to analyze some model approaches which allow to lower the taxable base with the cost of equity financing. Some practical experiences form several European countries are analyzed which enables to distinguish between classical model, incremental model and incremental model with a dual tax rate.