You need to file a W-9. Below is a citation from the IRS instructions for Form W-8BEN at:
https://www.irs.gov/pub/irs-pdf/iw8ben.pdf
"Do not use Form W-8BEN if
you are described below.
You are a foreign entity
documenting your foreign status, documenting your chapter 4 status, or claiming
treaty benefits. Instead, use Form W-8BEN-E.
You are a U.S. citizen (even if
you reside outside the United States) or other U.S. person (including a resident
alien individual). Instead, use Form W-9 to document your status as a U.S.
person.
You are acting as a foreign
intermediary (that is, acting not for your own account, but for the account of
others as an agent, nominee, or custodian). Instead, provide Form W-8IMY.
You are a nonresident alien
individual who claims exemption from withholding on compensation for
independent or dependent personal services performed in the United States.
Instead, provide Form 8233 or Form W-4.
You are receiving income that
is effectively connected with the conduct of a trade or business in the United
States, unless it is allocable to you through a partnership. Instead, provide
Form W-8ECI. If any of the income for which you have provided a Form W-8BEN
becomes effectively connected, this is a change in circumstances and Form
W-8BEN is no longer valid with respect to such income. You must file Form
W-8ECI. See Change in circumstances, later."
