Nobody enjoys paying taxes! The State being regarded for the majority of the taxpayers as a "spoliator" which comes to draw in the pockets of its subjects in a compulsory way, the incomes which those painfully gained and duly deserved! In spite of this negative conception of the payment of the tax, the Ivory Coast opted for the declarative system. The declarative system of the tax is defined as a system by which the taxpayers themselves declare to the tax authorities the taxable matter, calculate the amount of the tax and come spontaneously to pay the said amount at the tax office. In the declarative system, taxpayers have an active role. In return for the declarative system, the tax authorities carry out controls to ensure the accuracy of the amounts declared and paid by the taxpayer. This book will present the real basis for the choice of the declarative system of the Ivorian tax, to expand on the implementation of this system, to highlight its limitations and to inform the reader on the various tax audits conducted by the tax administration and its means of coercion.