An orphan structure is a financing term referring to a company whose shares are held by a trustee on a non-charitable purpose trust. The company is said to be an "orphan" as it is not beneficially owned by any natural person.
Orphan structures are usually used in offshore structures to ensure that the assets and liabilities of the subject company are treated as "off-balance-sheet" with respect to the sponsor of the structure. Other reasons for creating an orphan structure are to avoid or minimise regulation which might otherwise apply to a structure, and to ensure that the company is "bankruptcy remote" from companies in the same group as the sponsor.
Orphan structures are relatively common features of securitisation vehicles, where the asset backed bonds are issued by the orphan company.