Tax has been one of the most important instruments of the states in financing public spending throughout history. The audit of tax which is the most important financing instrument of the state, is based on economic, social and legal reasons. The impact of a strong audit in eliminating the disruptions that will arise in a tax system based on principle of statement is undeniable and the most important task in this area is on shoulder of those working in this field. The function of the tax audit is to ensure that the tax administration and taxpayers act in accordance with the legislation. For this reason, an existence of efficient, effective, transparent and accountable tax audit is important. E-applications in public administration structures have increased in accordance with information and communication technologies developed recently. In the study, the future of tax audit is evaluated within the framework of block chain applications frequently mentioned in recent years. It has been concluded that the block chain will be highly effective in tax audit as in other areas in the future and it will expedite tax collection and play an active role against black economy.