(a) Tiered partnerships. An upper-tier partnership's share of the liabilities of a lower-tier partnership (other than any liability of the lower-tier partnership that is owed to the upper-tier partnership) is treated as a liability of the upper-tier partnership for purposes of applying section 752 and the regulations thereunder to the partners of the upper-tier partnership.

(b) Related person definition—(1) In general. A person is related to a partner if the person and the partner bear a relationship to each other that is specified in section 267(b) or 707(b)(1), subject to the following modifications:

(i) Substitute “80 percent or more” for “more than 50 percent” each place it appears in those sections;

(ii) A person's family is determined by excluding brothers and sisters; and

(iii) Disregard sections 267(e)(1) and 267(f)(1)(A).

(2) Person related to more than one partner—(i) In general. If, in applying the related person rules in paragraph (b)(1) of this section, a person is related to more than one partner, paragraph (b)(1) of this section is applied by treating the person as related only to the partner with whom there is the highest percentage of related ownership. If two or more partners have the same percentage of related ownership and no other partner has a greater percentage, the liability is allocated equally among the partners having the equal percentages of related ownership.

(ii) Natural persons. For purposes of determining the percentage of related ownership between a person and a partner, natural persons who are related by virtue of being members of the same family are treated as having a percentage relationship of 100 percent with respect to each other.

(iii) Related partner exception. Notwithstanding paragraph (b)(1) of this section (which defines related person), persons owning interests directly or indirectly in the same partnership are not treated as related persons for purposes of determining the economic risk of loss borne by each of them for the liabilities of the partnership. This paragraph (iii) does not apply when determining a partner's interest under the de minimis rules in §§ 1.752-2 (d) and (e).

(iv) Special rule where entity structured to avoid related person status—(A) In general. If—

(1) A partnership liability is owed to or guaranteed by another entity that is a partnership, an S corporation, a C corporation, or a trust;

(2) A partner or related person owns (directly or indirectly) a 20 percent or more ownership interest in the other entity; and

(3) A principal purpose of having the other entity act as a lender or guarantor of the liability was to avoid the determination that the partner that owns the interest bears the economic risk of loss for federal income tax purposes for all or part of the liability;

(B) Ownership interest. For purposes of paragraph (b)(2)(iv)(A) of this section, a person's ownership interest in:

(1) A partnership equals the partner's highest percentage interest in any item of partnership loss or deduction for any taxable year;

(2) An S corporation equals the percentage of the outstanding stock in the S corporation owned by the shareholder;

(3) A C corporation equals the percentage of the fair market value of the issued and outstanding stock owned by the shareholder; and

(4) A trust equals the percentage of the actuarial interests owned by the beneficial owner of the trust.

(C) Example. Entity structured to avoid related person status. A, B, and C form a general partnership, ABC. A, B, and C are equal partners, each contributing $1,000 to the partnership. A and B want to loan money to ABC and have the loan treated as nonrecourse for purposes of section 752. A and B form partnership AB to which each contributes $50,000. A and B share losses equally in partnership AB. Partnership AB loans partnership ABC $100,000 on a nonrecourse basis secured by the property ABC buys with the loan. Under these facts and circumstances, A and B bear the economic risk of loss with respect to the partnership liability equally based on their percentage interest in losses of partnership AB.

(c) Limitation. The amount of an indebtedness is taken into account only once, even though a partner (in addition to the partner's liability for the indebtedness as a partner) may be separately liable therefor in a capacity other than as a partner.

(d) Time of determination. A partner's share of partnership liabilities must be determined whenever the determination is necessary in order to determine the tax liability of the partner or any other person. See § 1.705-1(a) for rules regarding when the adjusted basis of a partner's interest in the partnership must be determined.