(a) Remuneration paid for services performed within Puerto Rico for an employer (other than the United States or any agency thereof) by a citizen of the United States does not constitute wages and hence is not subject to withholding, if it is reasonable to believe that during the entire calendar year the employee will be a bona fide resident of Puerto Rico. The reasonable belief contemplated by section 3401(a)(8)(C) may be based upon any evidence reasonably sufficient to induce such belief, even though such evidence may be insufficient upon closer examination by the district director or the courts finally to establish that the employee was a bona fide resident of Puerto Rico for the entire calendar year.

(b) The employer may, in the absence of cause for a reasonable belief to the contrary, presume that an employee will be a bona fide resident of Puerto Rico during the entire calendar year.

(1) Unless the employee is known by the employer to have maintained his abode at a place outside Puerto Rico at some time during the current or the preceding calendar year; or

(2) In any case where the employee files with the employer a statement (containing a declaration under the penalties of perjury that such statement is true to the best of the employee's knowledge and belief) that such employee has at all times during the current calendar year been a bona fide resident of Puerto Rico and that he intends to remain a bona fide resident of Puerto Rico during the entire remaining portion of such current calendar year.

(c) This section has no application to remuneration paid to a citizen of the United States for services performed in Puerto Rico as an employee of the United States or any agency thereof.