W-8 form is an Internal Revenue Service (IRS) form that allows non-US individuals and businesses to confirm they are not US taxpayers. An SPV Organizer should collect a completed W8 (W8 BEN and W8 BEN-E) from each of their non US investors. A completed W8 form allows for an SPV tax return (form 1065) to be properly prepared and in some cases, obtaining a W8 from non US investors provides the SPV investors with an exemption from specified U.S. information return reporting and backup withholding regulations.
Read more: http://www.investopedia.com/terms/w/w8form.asp#ixzz4EK9jaG8y