For the Brazilian tax administration, the analysis begins with defining the nature of the contract to determine whether it can be considered a cost-sharing agreement or a service agreement. Table 1 illustrates the differences between service agreements and cost-sharing agreements. Opinion 45 confirmed the administrative philosophy of the CFS provided in Circular 2 and stressed the importance of the att-end principle and the cost-benefit comparison principle in these agreements. The growth of economic groups has led to a general increase in cooperation agreements. According to their modern definition, economic groups often operate through a number of companies in different sectors, both in the domestic market and in the international market. The advent of the new model led to the signing of agreements with the aim of centralizing a large number of non-essential joint business activities in a single company. . . .