A subsidiary, in business matters, is an entity that is controlled by a bigger and more powerful entity. The controlled entity is called a company, corporation, or limited liability company, and the controlling entity is called its parent (or the parent company). The reason for this distinction is that a lone company cannot be a subsidiary of any organization; only an entity representing a legal fiction as a separate entity can be a subsidiary. While individuals have the capacity to act on their own initiative, a business entity can only act through its directors, officers and employees.

The most common way that control of a subsidiary is achieved is through the ownership of shares in the subsidiary by the parent. These shares give the parent the necessary votes to determine the composition of the board of the subsidiary and so exercise control. This gives rise to the common presumption that 50% plus one share is enough to create a subsidiary. There are, however, other ways that control can come about and the exact rules both as to what control is needed and how it is achieved can be complex (see below). A subsidiary may itself have subsidiaries, and these, in turn, may have subsidiaries of their own. A parent and all its subsidiaries together are called a group, although this term can also apply to cooperating companies and their subsidiaries with varying degrees of shared ownership.

Subsidiaries are separate, distinct legal entities for the purposes of taxation and regulation. For this reason, they differ from divisions, which are businesses fully integrated within the main company, and not legally or otherwise distinct from it.

Subsidiaries are a common feature of business life and most if not all major businesses organize their operations in this way. Examples include holding companies such as Berkshire Hathaway1, Time Warner, or Citigroup as well as more focused companies such as IBM, or Xerox Corporation. These, and others, organize their businesses into national or functional subsidiaries, sometimes with multiple levels of subsidiaries.

An operating subsidiary is a business term frequently used within the United States railroad industry. In the case of a railroad, it refers to a company that is a subsidiary but operates with its own identity, locomotives and rolling stock.

In contrast, a non-operating subsidiary would exist on paper only (i.e. stocks, bonds, articles of incorporation) and would use the identity and rolling stock of the parent company. __NOTOC__

Control

The word "control" used in the definition of "subsidiary" is generally taken to include both practical and theoretical control. Thus, reference to a body which "controls the composition" of another body's board is a reference to control in principle, while reference to being are able to cast more than half of the votes at a general meeting, whether legally enforceable or not, refers to theoretical power. The fact that a company has a holding of less than 50% plus one share which, because the holdings of others are widely dispersed, gives effective control is not enough to give that company 'control' for the purpose of determining whether it is a subsidiary.