A subordinate organization is one that is under control of the central organization. According to the United States IRS Publication 557 (Rev. Oct. 2010), Tax-Exempt Status for Your Organization this is the definition for a subordinate organization:
"A subordinate organization is a chapter, local, post or unit of a central organization. A central organization may be a subordinate itself, such as a state organization that has subordinate units and is itself affiliated with a national (central) organization."[1]
A subordinate organization may or may not be incorporated, but it must have an organizing document. A subordinate that is organized and operated in a foreign country may not be included in a Group Exemption Letter (GEL). A subordinate described in section 501(c)(3) may not be included in a group exemption letter if it is a private foundation described in section 509(c).