Partnerships subject to withholding under section 1446 may require signed Forms W-9 from its U.S. partners to overcome any presumptions of foreign status and to avoid withholding on the partner's allocable share of the partnership's effectively connected taxable income. For more information, see Regulations section 1.1446-1(c). The final regulations are published as Treasury Decision 9200 on page 1158 of Internal Revenue Bulletin 2005-23 and are available at www.irs.gov/pub/irs-irbs/irb05-23.pdf.