What is Form W-9, and why is it important?

Form W-9(Request for Taxpayer Identification Number and Certification) is the IRS tax form that specifies the name, address, and Taxpayer Identification Number(TIN) for employment purposes. The person who completes Form W-9 is not an employee of the company but earns some income from the company(i.e., Independent contractors, freelancers, and more).