What is a W-9? Why was I sent one?

A W-9 is a form issued by the IRS that is used by companies to request tax information, specifically your TIN or tax identification number. A blank form is typically sent out to businesses or self employed individuals that have been hired to provide work or other services for another company as an independent contractor. When you present a W9 to another company you are basically certifying that the tax ID that you have provided is accurate.