Single market

A common market is usually referred to as the first stage towards the creation of a single market. It usually is built upon a free trade area with no tariffs for goods and relatively free movement of capital, workers and services, but not so advanced in reduction of other trade barriers.

A unified market is the last stage and ultimate goal of a single market. It requires the total free movement of goods and services, capital and people without regard to national boundaries.

Integration phases

A common market allows for the free movement of capital and services but large amounts of trade barriers remain. It eliminates all quotas and tariffs – duties on imported goods – from trade in goods within it. However non-tariff barriers to trade remain, such as differences between the Member States' rules on product safety, packaging requirements and national administrative procedures. These prevent manufacturers from marketing the same goods in all member states. The objective of a common market is most often economic convergence and the creation of an integrated single market. It is sometimes considered as the first stage of a single market. The European Economic Community was the first large-scale example of a common market.

A single market allows for people, goods, services and capital to move around a union as freely as they do within a single country – instead of being obstructed by national borders and barriers as they were in the past. Citizens can study, live, shop, work and retire in any member state. Consumers enjoy a vast array of products from all member states and businesses have unrestricted access to more consumers. A single market is commonly described as "frontier-free". However, several barriers remain such as differences in national tax systems, differences in parts of the services sector and different requirements for e-commerce. In addition separate national markets still exist for financial services, energy and transport. Laws concerning the recognition of professional qualifications also may not be fully harmonized. The Eurasian Economic Union, the Gulf Cooperation Council, CARICOM and the European Union are current examples of single markets, although the GCC's single market has been described as "malfunctioning" in 2014. The European Union is the only economic union whose objective is "completing the single market".

A completed, unified market usually refers to the complete removal of barriers and integration of the remaining national markets. Complete economic integration can be seen within many countries, whether in a single unitary state with a single set of economic rules, or among the members of a strong national federation. For example, the sovereign states of the United States do to some degree have different local economic regulations (e.g. licensing requirements for professionals, rules and pricing for utilities and insurance, consumer safety laws, environmental laws, minimum wage) and taxes, but are subordinate to the federal government on any matter of interstate commerce the national government chooses to assert itself. Movement of people and goods among the states is unrestricted and without tariffs.