26 U.S. Code § 1474 - Special rules
Every person required to deduct and withhold any tax under this chapter is hereby made liable for such tax and is hereby indemnified against the claims and demands of any person for the amount of any payments made in accordance with the provisions of this chapter.
Except as provided in paragraph (2), the determination of whether any tax deducted and withheld under this chapter results in an overpayment by the beneficial owner of the payment to which such tax is attributable shall be made as if such tax had been deducted and withheld under subchapter A of chapter 3.
No credit or refund shall be allowed or paid with respect to any tax properly deducted and withheld under this chapter unless the beneficial owner of the payment provides the Secretary such information as the Secretary may require to determine whether such beneficial owner is a United States owned foreign entity (as defined in section 1471(d)(3)) and the identity of any substantial United States owners of such entity.
For purposes of this chapter, rules similar to the rules of section 3406(f) shall apply.
The Secretary shall provide for the coordination of this chapter with other withholding provisions under this title, including providing for the proper crediting of amounts deducted and withheld under this chapter against amounts required to be deducted and withheld under such other provisions.
Any tax deducted and withheld pursuant to an agreement described in section 1471(b) shall be treated for purposes of this title as a tax deducted and withheld by a withholding agent under section 1471(a).
The Secretary shall prescribe such regulations or other guidance as may be necessary or appropriate to carry out the purposes of, and prevent the avoidance of, this chapter.