Bringing existing financial models closer to real practice is the most important challenge in precision finance. Over the past couple of years, the two main theories of the capital structure (Brusov–Filatova–Orekhova (BFO) and Modigliani–Miller (MM)) have been adapted to the established financial practice of the functioning of companies, taking into account the real conditions of their work. They are generalized to the case of variable income, to paying income tax with arbitrary frequency, to the advance payments of income tax etc. Taking these effects into account significantly changed the results of both theories and brought both theories closer to reality.