26 CFR 521.105 - Scope of convention with respect to determination of “industrial or commercial profits”.
(a) General. Article III of the convention adopts the principle that an enterprise of one of the contracting States shall not be taxable by the other contracting State upon its industrial or commercial profits unless it has a permanent establishment in the latter State. Hence, a Danish enterprise is subject to United States tax upon its industrial and commercial profits to the extent of such profits from sources within the United States only if it has a permanent establishment within the United States. From the standpoint of Federal income taxation, the article has application only to a Danish enterprise and to the industrial and commercial income thereof from sources within the United States. It has no application for example, to compensation for labor or personal services performed in the United States nor to income derived from real property located in the United States, including rentals and royalties therefrom, nor to gains from the sale or disposition of such property, nor to interest, dividends, royalties, other fixed or determinable annual or periodical income and gains derived from the sale or exchange of capital assets.
(b) No United States permanent establishment. A nonresident alien (including a nonresident alien individual, fiduciary and partnership) who is a resident of Denmark or a Danish corporation, carrying on an enterprise in Denmark and having no permanent establishment in the United States, is not for taxable years beginning on or after January 1, 1948, subject to United States income tax upon industrial or commercial profits from sources within the United States. For example, if the Danish enterprise carried on by such alien or corporation sells, in 1948, merchandise, such as silverware, dairy products, or liquors, through a bona fide commission agent or broker in the United States acting in the ordinary course of his business as such agent or broker, the resulting profits are, under the terms of Article III of the convention, exempt from United States income tax. Likewise no permanent establishment exists and no United States income tax attaches to such profits if such enterprise, through its sales agents in the United States, secures orders for its products, the sales being made in Denmark.
(c) United States permanent establishment. A nonresident alien (including a nonresident alien individual, fiduciary and partnership), who is a resident of Denmark, or a Danish corporation, whether or not carrying on a Danish enterprise, having a permanent establishment in the United States, is subject to tax upon industrial or commercial profits from sources within the United States to the same extent as are nonresident aliens and foreign corporations engaged in trade or business therein. In the determination of the income taxable to such alien or foreign corporation all industrial and commercial profits from sources within the United States shall be deemed to be allocable to the permanent establishment in the United States. Hence, for example, if a Danish enterprise having a permanent establishment in the United States sells in the United States, through a commission agent therein goods produced in Denmark, the resulting profits derived from United States sources from such transactions are allocable to such permanent establishment even though such transactions were carried on independently of such establishment. In determining industrial and commercial profits no account shall be taken of the mere purchase of merchandise within the United States by the Danish enterprise. The industrial or commercial profits of the permanent establishment shall be determined as if the establishment were an independent enterprise engaged in the same or similar activities and dealing at arm's length with the enterprise of which it is a permanent establishment.