26 CFR 1.267(a)-1 - Deductions disallowed.
(a)Losses. Except in cases of distributions in corporate liquidations, no deduction shall be allowed for losses arising from direct or indirect sales or exchanges of property between persons who, on the date of the sale or exchange, are within any one of the relationships specified in section 267(b). See § 1.267(b)-1.
(b)Unpaid expenses and interest.
(1) No deduction shall be allowed a taxpayer for trade or business expenses otherwise deductible under section 162, for expenses for production of income otherwise deductible under section 212, or for interest otherwise deductible under section 163:
(i) If, at the close of the taxpayer's taxable year within which such items are accrued by the taxpayer or at any time within 2 1/2 months thereafter, both the taxpayer and the payee are persons within any one of the relationships specified in section 267(b) (see § 1.267(b)-1); and
(ii) If the payee is on the cash receipts and disbursements method of accounting with respect to such items of gross income for his taxable year in which or with which the taxable year of accrual by the debtor-taxpayer ends; and
(iii) If, within the taxpayer's taxable year within which such items are accrued by the taxpayer and 2 1/2 months after the close thereof, the amount of such items is not paid and the amount of such items is not otherwise (under the rules of constructive receipt) includible in the gross income of the payee.
(2) The provisions of section 267(a)(2) and this paragraph do not otherwise affect the general rules governing the allowance of deductions under an accrual method of accounting. For example, if the accrued expenses or interest are paid after the deduction has become disallowed under section 267(a)(2), no deduction would be allowable for the taxable year in which payment is made, since an accrual item is deductible only in the taxable year in which it is properly accruable.
(3) The expenses and interest specified in section 267(a)(2) and this paragraph shall be considered as paid for purposes of that section to the extent of the fair market value on the date of issue of notes or other instruments of similar effect received in payment of such expenses or interest if such notes or other instruments were issued in such payment by the taxpayer within his taxable year or within 2 1/2 months after the close thereof. The fair market value on the date of issue of such notes or other instruments of similar effect is includible in the gross income of the payee for the taxable year in which he receives the notes or other instruments.
(4) The provisions of this paragraph may be illustrated by the following example:
(c)Scope of section. Section 267(a) requires that deductions for losses or unpaid expenses or interest described therein be disallowed even though the transaction in which such losses, expenses, or interest were incurred was a bona fide transaction. However, section 267 is not exclusive. No deduction for losses or unpaid expenses or interest arising in a transaction which is not bona fide will be allowed even though section 267 does not apply to the transaction.