Employee compensation
(ii) Employee compensation(A) In general. Except as provided in paragraph (b)(2)(ii)(B) or (C) of this section, in the case of compensation for labor or personal services performed partly within and partly without the United States by an individual as an employee, the part of such compensation that is attributable to the labor or personal services performed within the United States, and that is therefore included in gross income as income from sources within the United States, is determined on a time basis, as defined in paragraph (b)(2)(ii)(E) of this section. (B) Certain fringe benefits sourced on a geographical basis. Except as provided in paragraph (b)(2)(ii)(C) of this section, items of compensation of an individual as an employee for labor or personal services performed partly within and partly without the United States that are described in paragraphs (b)(2)(ii)(D)(1) through (6) of this section are sourced on a geographical basis in accordance with those paragraphs. (C) Exceptions and special rules(1) Alternative basis(i) Individual as an employee generally. An individual may determine the source of his or her compensation as an employee for labor or personal services performed partly within and partly without the United States under an alternative basis if the individual establishes to the satisfaction of the Commissioner that, under the facts and circumstances of the particular case, the alternative basis more properly determines the source of the compensation than a basis described in paragraph (b)(2)(ii)(A) or (B), whichever is applicable, of this section. An individual that uses an alternative basis must retain in his or her records documentation setting forth why the alternative basis more properly determines the source of the compensation. In addition, the individual must provide the information related to the alternative basis required by applicable Federal tax forms and accompanying instructions.