My diploma thesis is focused on the optimization of corporate income tax. The thesis is divided into the theoretical and practical part. In the theoretical part are described terms such as taxpayers, subject of tax, tax base, tax calculation or when the tax is payable. The practical part begins with the characteristic of the company, followed by the calculation of the tax liability and the optimization of the corporate income tax. The aim of the thesis was to find the optimal variant of the calculation of the tax liability in 2015 and 2016 in the selected trading company. In the diploma thesis it was concluded that the best option for optimization is creation of reserves for repair of tangible assets or other tax deductible reserves.

This article discusses the treatment of the income tax of second category generated from the sale of real property made by individuals. Its development will focus on the following points:1) The tax determination described sequentially and according to law; 2) The exceptionalcases where there is not capital gain on the sale of a real property; 3) The determination ofthe tax basis in the cases where the transferor acquired free of charge the property that willbe transferred; 4) The obligation of using means of payment accepted by the banking andfinancial system in the operation; 5) The opportunity to pay the tax; 6) The exchange rate tobe used when the operation is performed in foreign currency; 7) The resolution of everydaylife cases related to the tax calculation; and 8) The summary of the main points of this article. / El presente artículo versa sobre el tratamiento del Impuesto a la Renta de segunda categoría generado por la enajenación de inmuebles por parte de personas naturales. Su desarrollo gira en torno a los siguientes puntos: 1) El cálculo del Impuesto descrito de manera secuencial y según la base normativa; 2) Los supuestos excepcionales en los que no se considera que se ha generado ganancia de capital en la enajenación de un inmueble; 3) La determinación del costo computable en aquellos casos en que el enajenante adquirió de forma gratuita el inmueble que va a ser enajenado; 4) La obligación de bancarizar la operación; 5) La oportunidad de pago del impuesto; 6) El tipo de cambio a utilizar cuando la operación se realiza en moneda extranjera; 7) La resolución de casos de la vida cotidiana relacionados con el cálculo del impuesto; y, 8) El resumen de los puntos principales del artículo.