Internal Revenue Code
§ 513 Unrelated trade or business.
(a) General rule.
The term “unrelated trade or business” means, in the case of any organization subject to the tax imposed by section 511 , any trade or business the conduct of which is not substantially related (aside from the need of such organization for income or funds or the use it makes of the profits derived) to the exercise or performance by such organization of its charitable, educational, or other purpose or function constituting the basis for its exemption under section 501 (or, in the case of an organization described in section 511(a)(2)(B) , to the exercise or performance of any purpose or function described in section 501(c)(3) ), except that such term does not include any trade or business—
(1) in which substantially all the work in carrying on such trade or business is performed for the organization without compensation; or
(2) which is carried on, in the case of an organization described in section 501(c)(3) or in the case of a college or university described in section 511(a)(2)(B) , by the organization primarily for the convenience of its members, students, patients, officers, or employees, or, in the case of a local association of employees described in section 501(c)(4) organized before May 27, 1969, which is the selling by the organization of items of work-related clothes and equipment and items normally sold through vending machines, through food dispensing facilities, or by snack bars, for the convenience of its members at their usual places of employment; or
(3) which is the selling of merchandise, substantially all of which has been received by the organization as gifts or contributions.
(b) Special rule for trusts.
The term “unrelated trade or business” means, in the case of—
(1) a trust computing its unrelated business taxable income under section 512 for purposes of section 681 ; or
(2) a trust described in section 401(a) , or section 501(c)(17) , which is exempt from tax under section 501(a) ;
any trade or business regularly carried on by such trust or by a partnership of which it is a member.