The creation of free trade zones is seen as an exception to the most privileged principle of the World Trade Organization (WTO), since the preferences of the parties to the exclusive granting of a free trade area go beyond their accession obligations.  Although GATT Article XXIV authorizes WTO members to establish free trade zones or to conclude interim agreements necessary for their establishment, there are several conditions relating to free trade zones or interim agreements leading to the creation of free trade zones. There are currently a number of free trade agreements in the United States. These include multi-nation agreements such as the North American Free Trade Agreement (NAFTA), which includes the United States, Canada and Mexico, and the Central American Free Trade Agreement (CAFTA), which includes most Central American nations. There are also separate trade agreements with nations, from Australia to Peru. Governments with free trade policies or agreements do not necessarily abandon control over imports and exports or eliminate all protectionist policies. In modern international trade, few free trade agreements lead to completely free trade. These agreements between three or more countries are the most difficult to negotiate. The larger the number of participants, the more difficult the negotiations. They are, by nature, more complex than bilateral agreements, insofar as each country has its own needs and requirements. First, the parties that signed a free trade area applicable to trade with non-parties to that free trade area at the time of the creation of that free trade area must not be higher or more restrictive than tariffs and other rules applicable in the same signatory countries prior to the creation of the free trade area.
In other words, the creation of a free trade area to give preferential treatment to their members is legitimate under WTO law, but parties to a free trade area are not allowed to treat non-parties less favourably than before the creation of the territory. A second requirement under Article XXIV is that tariffs and other trade barriers must be eliminated primarily for all trade within the free trade area.  On the other hand, some local industries benefit. They are finding new markets for their duty-free products. These industries are growing and employing more labour. These compromises are the subject of endless debate among economists. This helps increase U.S. exports to the rest of the world, where 95% of our potential customers live.
Increased U.S. exports are driving up business turnover, boosting our economy and adding to the 38 million U.S. jobs currently dependent on trade. Our nation currently has only 11 free trade agreements with 17 countries, but there are nearly 300 non-U.S. states. Agreements that are in effect all over the world. Many others are being negotiated without the United States. With about 200 nations in the world, the potential to make the show fairer for the United States seems to preserve our competitive advantage and continue to develop our economy through free trade agreements. Together, these agreements mean that about half of all goods entering the United States enter duty-free, according to the government. The average import duty on industrial products is 2%. When you decide where you want to export your goods or services, you have to ask yourself whether or not there is a free trade agreement.
With a free trade agreement, you can expect fewer barriers, lower tariffs (if any) and more generous trade quotas (if any). Given that mfN duties would be applied to many uk exports to the EU, this could mean that many exporters will become less price competitive than their EU counterparts and those of countries with which the EU has preferential trade relations.