その年分の不動産所得の金額、事業所得の金額又は雑所得の金額（事業所得の金額及び雑所得の金額のうち山林の伐採又は譲渡に係るもの並びに雑所得の金額のうち第三十五条第三項（公的年金等の定義）に規定する公的年金等に係るものを除く。）の計算上必要経費に算入すべき金額は、別段の定めがあるものを除き、これらの所得の総収入金額に係る売上原価その他当該総収入金額を得るため直接に要した費用の額及びその年における販売費、一般管理費その他これらの所得を生ずべき業務について生じた費用（償却費以外の費用でその年において債務の確定しないものを除く。）の額とする。
Except as provided otherwise, the amounts that are to be included in the necessary expenses that are used to calculate the real property income, business income, or miscellaneous income for the year (other than any business income or miscellaneous income arising from the felling of trees in forested land or the transfer of forested land, and other than miscellaneous income arising from a public pension or retirement package as prescribed in Article 35, paragraph (3) (Definition of Public Pensions and Retirement Packages)) are the costs of goods sold to generate the gross revenue in that income type or other expenses directly necessary to the taxpayer's acquisition of gross revenue in that income type, as well as sales expenses, general administrative expenses, and other expenses for business operations in the year that are meant to generate that type of income (excluding any expense, other than a depreciation allowance, for which the taxpayer's liability does not become fixed during that year).
山林につきその年分の事業所得の金額、山林所得の金額又は雑所得の金額の計算上必要経費に算入すべき金額は、別段の定めがあるものを除き、その山林の植林費、取得に要した費用、管理費、伐採費その他その山林の育成又は譲渡に要した費用（償却費以外の費用でその年において債務の確定しないものを除く。）の額とする。
Except as provided otherwise, the amounts that are to be included in the necessary expenses that are used to calculate business income, timber income, or miscellaneous income are planting expenses, acquisition costs, maintenance expenses, felling expenses, and any other expenses needed to cultivate or transfer forested land (excluding any expense, other than a depreciation allowance, for which the taxpayer's liability does not become fixed during that year).