The “internal market” is defined as a “market” within a defined territorial area in which a free exchange of goods, services, capital and employees is guaranteed under uniform conditions.

The central prerequisites for the emergence of an “internal market” are territorial disjunction and sovereign lawmaking. Therefore, a “internal market” usually arises on the territory of a sovereign entity or alliance of such entities. A “internal market is often understood as a “market” within a state or a supranational alliance, in which a free exchange of goods, services, capital and employees is guaranteed under uniform conditions. The word “internal market” is therefore often used synonymously with the term “domestic market”. With regard to the “internal market” of the European Union the term “single market” is common.

The concept of the “internal market” thus understood is a spatial concretisation of the general market concept, which is intended to clarify the distinction to market conditions and transaction modalities beyond these borders.