 The ADIT exams are widely considered to be technically rigorous, with demanding pass requirements for each of the three examinations.Successful candidates take an average of two to three years to earn their ADIT credential.ADIT covers a broad range of topics relating to the OECD Model Convention, double tax treaties, a select number of countries’ tax regimes regarding international tax matters, Transfer Pricing, specific areas of taxation, and transnational tax issues relating to the EU.