Establishment is the generic term used to refer to the building blocks of legal entities. Each legal entity is made up of at least one establishment. These 100 percent owned and controlled entities can also be referred as branches, divisions, establishments (domestic or foreign), inventory organizations, physical locations (for example, manufacturing plants and warehouses). They can be a physical (address) or logical (specific activity) subdivision of the legal entity.

In many countries, establishments need to be registered with local regulatory bodies and may have their own activity codes (such as the NACE code in Europe or the SIC code in the U.S.). Dun & Bradstreet (D&B) have DUN numbers for them as well. They have significant existence (their own address, often supporting local taxes and regulations, in some countries a threshold of number of employee per site), or significant business autonomy (may have their activity code, their own budget, handle their own bank accounts). They are not liable to the outside world (cannot be sued separately in court). They support or represent local or distant registrations of the legal entity. They also represent autonomous business units.

To fulfill registration requirements in some countries at a local level, a legal entity must register a main establishment. For this reason, the main establishment is created automatically when you create a legal entity. While establishments may or may not be located in the country of the legal entity, the main establishment is always located in the country of the legal entity. It is the main site (location) of a legal entity, which supports specific duties related to coordinating business operations and compliance with legislation and reporting needs for the legal entity.