以下是引用fyan在2006-6-4 1:46:00的发言：
W-7 is for ITIN. W-9 is for other purposes.

谢谢楼上纠正啊，我给看错了

Purpose of Form W-9：

A person who is required to file an information return with the
IRS, must obtain your correct taxpayer identification number
(TIN) to report, for example, income paid to you, real estate
transactions, mortgage interest you paid, acquisition or
abandonment of secured property, cancellation of debt, or
contributions you made to an IRA.