I am not a Tax Lawyer, Nor do I play Dan Evans on the internet.
I am not a Certified Public Accountant, Nor do I play Paul Thomas on the internet.
I am not an Enrolled Agent, Nor do I play Richard Macdonald on the internet.
DO NOT TAKE MY WORD FOR ANYTHING ON THIS PAGE.
Go look it up for yourself.
The "certification" purposes of Form W-9:
The purpose of the Form W-9 is to transmit certain information to a "withholding agent".
Let's see who a "withholding agent" is.
Sections 1441, 1442, 1443, and 1461 deal with, respectively;
The IRC is the skeleton, the Regulations are the muscle.
The the term withholding agent means any person ... that has the control ... or payment of an item of income of a foreign person subject to withholding.
A "withholding agent" is anybody that pays a foreign person. Are you a foreign person? Is your boss a "withholding agent"?