It is also important to note that a free trade agreement is a mutual agreement, which is permitted by Article XXIV of the GATT. Autonomous trade regimes for developing and least developed countries are authorized by the decision adopted in 1979 by the signatories to the General Agreement on Tariffs and Trade (GATT) on differential and more favourable treatment, reciprocity and wider participation of developing countries (hereinafter referred to as the „enabling clause“). This is the WTO`s legal basis for the Generalised System of Preferences (GSP).  Free trade agreements and preferential trade regimes (as indicated by the WTO) are considered to be most-favoured-nation derogations.  9. The preferences referred to in Article I(2) shall not be affected by the establishment of a customs union or a free trade area, but may be eliminated or adapted through negotiations with the parties concerned.* This negotiation procedure with the parties concerned shall apply in particular to the elimination of preferences necessary to comply with the provisions of paragraphs 8(a)(i) and 8 (b). There are three different types of trade agreements. The first is a unilateral trade agreement This happens when one country wants to impose certain restrictions, but no other country wants them to be imposed. It also allows countries to reduce the number of trade restrictions. It is also something that is not frequent and could affect a country. Unlike a customs union, parties to a free trade agreement do not have common external tariffs, which means that they apply different tariffs and other directives to non-members. This feature allows non-parties to obtain footsp preferences under a free trade agreement by entering the market with the lowest external tariffs. Such a risk requires the introduction of rules for determining which originating products are eligible for preferences under a free trade agreement, a need that does not arise in the context of the creation of a customs union.
 In principle, a minimum volume of processing is required, resulting in a „substantial transformation“ of the goods in order for them to be considered originating. In defining the products originating in the ATP, the preferential rules of origin distinguish between originating and non-originating products: only the former are entitled to the preferential duties set by the FREE TRADE AGREEMENT, the latter must pay the most-favoured-nation duties.  A free trade agreement is an agreement between two or more countries in which countries agree, among other things, on certain obligations that affect trade in goods and services, investor protection and intellectual property rights. For the United States, the main objective of trade agreements is to reduce barriers to U.S. exports, protect U.S. competing interests abroad, and improve the rule of law in FTA partner countries. A trade agreement signed between more than two parties (usually in the neighbourhood or in the same region) is considered multilateral. These face the main obstacles – in the negotiation of the substance and in the implementation.
The more countries involved, the more difficult it is to achieve mutual satisfaction. Once this type of trade agreement is concluded, it will become a very powerful agreement. The larger the GDP of the signatories, the greater the impact on other global trade relations. The most important multilateral trade agreement is the North American Free Trade Agreement between the United States, Canada and Mexico.  Trade agreements that the WTO describes as preferential are also called regional rta, although they are not necessarily concluded by countries within a given region. As of July 2007, 205 agreements are currently in force. More than 300 have been notified to the WTO.  The number of free trade agreements has increased significantly over the past decade. .