This research focuses on studying and analyzing how far the establishment of a system for optimal retrieval, and dual based on two pillars, tax and Zakah allows to increase the tax revenue of the country. Thus, this study allows us to identify a set of factors that characterize the quality of the tax system (simplicity, equity, efficiency and fiscal neutrality) and may influence the country's tax revenues. We will try, too, to study how the introduction of a system of dual levy based on two pillars, tax and Zakah, will increase tax revenues via the weakening of the tax burden. The study was conducted among a sample of 112 professionals in accounting and taxation. Results show that improving the quality of Tunisian tax system via tax simplicity, tax fairness, tax efficiency and tax neutrality has a positive impact on tax revenue of the country. The study also shows that the introduction of a dual sampling system based on two pillars, tax and Zakah does not generate increased tax revenue of the country via the weakening of the tax burden.

Keywords: Tax, Zakah, Tunisia, post revolution