(a) In general. Sales of real property involving deferred payments include (1) agreements of purchase and sale which contemplate that a conveyance is not to be made at the outset, but only after all or a substantial portion of the selling price has been paid, and (2) sales in which there is an immediate transfer of title, the vendor being protected by a mortgage or other lien as to deferred payments.
(b) Classes of sales. Such sales, under either paragraph (a) (1) or (2) of this section, fall into two classes when considered with respect to the terms of sale, as follows:
(1) Sales of real property which may be accounted for on the installment method, that is, sales of real property in which (i) there are no payments during the taxable year of the sale or (ii) the payments in such taxable year (exclusive of evidences of indebtedness of the purchaser) do not exceed 30 percent of the selling price, or
(2) Deferred-payment sales of real property in which the payments received in cash or property other than evidences of indebtedness of the purchaser during the taxable year in which the sale is made exceed 30 percent of the selling price.
(c) Determination of ``selling price''. In the sale of mortgaged property the amount of the mortgage, whether the property is merely taken subject to the mortgage or whether the mortgage is assumed by the purchaser, shall, for the purpose of determining whether a sale is on the installment plan, be included as a part of the ``selling price''; and for the purpose of determining the payments and the total contract price as those terms are used in section 453, and Secs. 1.453-1 through 1.453-7, the amount of such mortgage shall be included only to the extent that it exceeds the basis of the property. The term ``payments'' does not include amounts received by the vendor in the year of sale from the disposition to a third person of notes given by the vendee as part of the purchase price which are due and payable in subsequent years. Commissions and other selling expenses paid or incurred by the vendor shall not reduce the amount of the payments, the total contract price, or the selling price. [T.D. 6500, 25 FR 11715, Nov. 26, 1960]