This article aims at showing the various daily form of management of tax illegalities. The study was made after an on-the-spot enquiry based on relations between taxpayers and tax officers. On the one hand, distinct control measures stem from the evolution of the sets of penalties. The development of data files has allowed intensifying control over illegalities among the working classes. On the other hand, information about better-off taxpayers remains difficult to access which gives them significant possibilities of fraud. In addition to these instituted inequalities, one has to add instructions from the top hierarchy: in the name of conciliation, high-ranking civil servants advocate leniency, a favor often enjoyed by the wealthiest. However, such infringements of the tax equality principle arouse strong resistance from civil servants responsible for conducting controls on a daily basis