§ 1.166-5. Nonbusiness debts.

The question whether a debt is a nonbusiness debt is a question of fact in each particular case. The determination of whether the loss on a debt's becoming worthless has been incurred in a trade or business of the taxpayer shall, for this purpose, be made in substantially the same manner for determining whether a loss has been incurred in a trade or business for purposes of section 165(c)(1). For purposes of subparagraph (2) of this paragraph, the character of the debt is to be determined by the relation which the loss resulting from the debt's becoming worthless bears to the trade or business of the taxpayer. If that relation is a proximate one in the conduct of the trade or business in which the taxpayer is engaged at the time the debt becomes worthless, the debt comes within the exception provided by that subparagraph. The use to which the borrowed funds are put by the debtor is of no consequence in making a determination under this paragraph. For purposes of section 166 and this section, a nonbusiness debt does not include a debt described in section 165(g)(2)(C). See § 1.165-5, relating to losses on worthless securities.

In 1956 A sells the business but retains the claim against B. The claim becomes worthless in A's hands in 1957. A's loss is not controlled by the nonbusiness debt provisions, since the original consideration has been advanced by A in his trade or business.

In 1956 A sells the business to C but sells the claim against B to the taxpayer, D. The claim becomes worthless in D's hands in 1957. During 1956 and 1957, D is not engaged in any trade or business. D's loss is controlled by the nonbusiness debt provisions even though the original consideration has been advanced by A in his trade or business, since the debt has not been created or acquired in connection with a trade or business of D and since in 1957 D is not engaged in a trade or business incident to the conduct of which a loss from the worthlessness of such claim is a proximate result.

In 1956 A dies, leaving the business, including the accounts receivable, to his son, C, the taxpayer. The claim against B becomes worthless in C's hands in 1957. C's loss is not controlled by the nonbusiness debt provisions. While C does not advance any consideration for the claim, or create or acquire it in connection with his trade or business, the loss is sustained as a proximate incident to the conduct of the trade or business in which he is engaged at the time the debt becomes worthless.

In 1956 A dies, leaving the business to his son, C, but leaving the claim against B to his son, D, the taxpayer. The claim against B becomes worthless in D's hands in 1957. During 1956 and 1957, D is not engaged in any trade or business. D's loss is controlled by the nonbusiness debt provisions even though the original consideration has been advanced by A in his trade or business, since the debt has not been created or acquired in connection with a trade or business of D and since in 1957 D is not engaged in a trade or business incident to the conduct of which a loss from the worthlessness of such claim is a proximate result.

In 1956 A dies; and, while his executor, C, is carrying on the business, the claim against B becomes worthless in 1957. The loss sustained by A's estate is not controlled by the nonbusiness debt provisions. While C does not advance any consideration for the claim on behalf of the estate, or create or acquire it in connection with a trade or business in which the estate is engaged, the loss is sustained as a proximate incident to the conduct of the trade or business in which the estate is engaged at the time the debt becomes worthless.

In 1956, A, in liquidating the business, attempts to collect the claim against B but finds that it has become worthless. A's loss is not controlled by the nonbusiness debt provisions, since the original consideration has been advanced by A in his trade or business and since a loss incurred in liquidating a trade or business is a proximate incident to the conduct thereof.