For the transition period, from the start of the common market through December 31, 1994, it was provided that member States would adopt a general regime of origin. This system was setup to settle controversies and safeguard covenants as well as a coordination to tackle dumping practices or disloyal policies from other States.

Tools used to build the common market were defined by several instruments: a free trade program that would allow "to reach December 31, 1994 with zero tariff, without non-tariffs restrictions on the whole tariff universe"; "the coordination of macroeconomic policies that would take place gradually and together with the tariffs reduction programs and the elimination of non-tariff restriction indicated in the previous item"; "an external common tariff which encourages the foreign competitiveness of the member States"; and "the undertaking of agreements from different sectors with the purpose of optimizing the use and motion of the production factors and reaching efficient operating scales".

Two bodies, one of them political in nature and the other one executive in nature, were established to administer the Treaty: the Common Market Council and the Common Market Group.

The Common Market Council, which became the superior body of "MERCOSUR" (Southern Common Market), is made up of the Foreign Affairs Ministers and the Ministers of Economy of the four countries. The Council's main task consists in the political management and the decision making power to assure the goals and fulfillment of the stated terms. The chairmanship of the Council rotates among the member States and in alphabetical order every six months.

The Common Market Group was made up as the executive body of MERCOSUR and it is coordinated by the Foreign Affairs Ministers. The functions of the Group consists of assuring the Treaty fulfillment; taking the necessary measures for the fulfillment of the decisions made up by the Council; suggesting firm measures for the application of the free trade program, the coordination of macroeconomic policies and the negotiation of agreements with third parties, and setting the work program that assures the movement towards the constitution of the common market.

The Common Market Group is made up of four regular members and four alternating members, who are representatives of the Ministries of Foreign Affairs, Economy or their equivalent bodies (sectors of Industry, Foreign Trade and/or Economic Coordination), and Central Banks.