An issuer corporate hierarchy is the record of ownership relationships between an issuer of securities and the other legal entities in its group: its immediate parent, its ultimate parent and its subsidiaries. It forms part of issuer reference data. Bonds and shares are often issued by financing subsidiaries or special purpose companies whose names give little indication of the group standing behind them, and the hierarchy makes that connection explicit.
Its main use is to add up risk. A firm that lends to, trades with and holds securities of several entities in one group needs their combined figure to apply a counterparty credit limit, to comply with large exposure limits and to measure concentration risk. The global legal entity identifier system publishes the direct and ultimate parents that entities report, and commercial vendors supply fuller trees. Definitions of control differ between sources, and mergers and disposals require constant updating.