The Moroccan tax system is essentially declarative, the taxpayers must declare spontaneously their profits and incomes and the control of the administration is often done a posteriori. This control is not done arbitrarily, but rather according to a procedure well determined by the legislator "the normal procedure of rectification following the verification of accounts", it is a set of techniques to control and ensure the sincerity of the accounts and declarations filed. When talking about this procedure, it is essential to remember that there are two main actors, namely the administration and the taxpayer, where the rules of the game are summarized in the framework of the powers of the administration and the definition of a protection framework for the taxpayer. To ensure this protection, the legislator has attributed a certain number of guarantees in the form of procedural rules that are imposed on the administration during the implementation of these control instruments, these rules are of fundamental scope.