A W-9 form is an Internal Revenue Service (IRS) tax form that is used to confirm a person's name, address, and taxpayer identification number (TIN) for employment or other income-generating purposes. The confirmation can be requested for either an individual defined as a U.S. citizen or a person defined as a resident alien. This document is usually request to contractors by mortgage companies when processing the fund release for monitored claims.

A W-9 form is also known as a Request for Taxpayer Identification Number and Certification form. All pages of Form W-9 are available on the IRS website. In addition, the form may include a specific set of instructions provided by the IRS.