Although the term tax transparency has recently become more popular, it has in fact long been recognized with its main aspects under different titles in tax law. Indeed, for example, tax payer's data collection to carry out its ultimate duty of tax collection by the tax administration (taxpayer's transparency toward tax administration), is one of the important tax procedure law issues studied under control or preparation actions of the tax administration. Similarly, the tax administration's duty of handling the data of taxpayers confidentially has been studied under tax privacy or tax secrecy for years. However, in the last decade, certain changes to add new dimensions to the concept have been observed: 1. due to digitalization, tax administration's data collection and data processing about the tax payer has been facilitated, 2. internationally, rapid development has been took placed in the information exchange between tax administrations, 3. some tools such as country by country reporting have gained importance in the fight against aggressive tax planning, 4. in some countries,tax administrations have been revealed to make secret agreements with multi- national companies to provide them advantageous tax practices. All these have made it necessary that while protecting taxpayer data, in some cases certain information be shared with the public for the public interest and careful consideration be given to tax administration's transparency to both the tax payer and the public.