IRS Form 8288
Most questions about FIRPTA can be answered by reading the instructions starting on the second page of Form 8288.
FIRPTA changes effective 11/3/03
FIRPTA Statement By Qualified Substitute
Withholding (Rev. & Taxation Code 18662)
California requires an additional 3-1/3% to be withheld unless certain exemptions apply. This is a link to the Franchise Tax Board's web page containing all the information you will need, including forms and instructions.
Hawaii Withholding (H.R.S. 235-68)
Hawaii requires an additional 5% to be withheld unless certain exemptions apply.
Explanation of Hawaii withholding
Hawaii withholding forms on Department of Taxation web site