When making payments for services rendered outside the United States, you must obtain an IRS Form W-8BEN.  The W-8BEN is required for several reasons:

• To establish that the vendor is not a U.S. person.
• To claim that the vendor is the beneficial owner of the income to which that payment applies.
• To certify that the income is not effectively connected with the conduct of a trade or business in the United States.

The W-8BEN must be submitted with the voucher at least 30 days prior to the day payment is due.  Failure to timely provide the W-8BEN may result in withholding at a rate of 30%.  Form W-8BEN is required for all forms of payment including but not limited to checks, wire transfers, foreign drafts.

Instructions for Form W-8BEN are also available through the IRS.