Apart from the problem of use of the tax havens in the financing of international crimes, the non-taxation of high amounts of funds brings some other problems such as reduction of the budget revenues of the states and the restriction of public expenditures. Therefore, the "tax havens" has become serious and current problem that needs to be resolved for the world economy. The Organisation for Economic Co-operation and Development (OECD) published a report in 1998 and declared a war against harmful tax competition. This report was the first wave of fighting against harmful tax competition. However, the proliferation of tax havens led to exist a new wave -especially after the global financial crisis- in combat with tax havens. This second wave was named "transparency" by OECD. The "transparency" revealed in OECD Base Erosion Profit Shifting -5 Action (2015 final report), which can be used as an instrument in fighting against tax havens, has be examined in the study.