Two main capital structure theories: Brusov–Filatova–Orekhova (BFO theory) and its perpetuity limit—Modigliani–Miller theory—describe the case of annual payments of tax of profit at the end of periods, but in practice these payments (1) are made more frequent: semiannually, quarterly, monthly; (2) could be made in advance. To study the influence of these two effects to main financial indicators of the company, such as the weighted average cost of capital, WACC, company value, V, and equity cost, ke, we modify the Modigliani–Miller theory for the case of arbitrary frequency of payments of tax on profit: for payments at the end of periods as well as for advanced payments. Account of two these effects leads to very important consequences. We show that: All these allow company choose the method of payments of tax of profit(at the end of period or in advance) and number of payments of tax of profit per year, as many, as it is profitable to it (of course, within actual tax legislation).