Financial Services

OUHSC Campus

Accounts Payable

Original W-8 Requirement

OUHSC Accounts Payable will accept a copy of a W-8 Substitute and make payments to the vendor without backup withholding for 90 days. On the 91st day the copy is no longer valid.  If an original signed form is not received by the 91st day the vendor will be subject to 38% Backup withholding (30% Federal 8% State).

Internal Revenue Code 1.1441-1(b)(3)(iv) states (iv) Grace period. A withholding agent may choose to apply the provisions of §1.6049-5(d)(2)(ii) regarding a 90-day grace period for purposes of this paragraph (b)(3) (by applying the term withholding agent instead of the term payor ) to amounts described in §1.1441-6(c)(2) and to amounts covered by a Form 8233 described in §1.1441-4(b)(2)(ii). Thus, for these amounts, a withholding agent may choose to treat an account holder as a foreign person and withhold under chapter 3 of the Internal Revenue Code (and the regulations thereunder) while awaiting documentation. For purposes of determining the rate of withholding under this section, the withholding agent must withhold at the unreduced 30-percent rate at the time that the amounts are credited to an account. However, a withholding agent who can reliably associate the payment with a withholding certificate that is otherwise valid within the meaning of the applicable provisions except for the fact that it is transmitted by facsimile may rely on that facsimile form for purposes of withholding at the claimed reduced rate.


Once the form is no longer valid OUHSC will:

  • Consider the payee as a foreign person (nonresident alien, foreign corporation, etc.)
  • Withhold U.S. federal income tax at the statutory rate of 30% and Oklahoma state rate of 8% on any future payments
  • Ignore any tax treaty claims,
  • Backup withhold federal and state income taxes on any previous payments, and
  • Report the payments at year-end on a Form 1042-S.