The I-9 and W-9 forms serve very different purposes: I-9 (Employment Eligibility Verification): Used for employees (W-2 workers) Verifies identity and employment authorization Required for all new hires, regardless of citizenship Completed by both the employee and the employer W-9 (Request for Taxpayer Identification Number and Certification): Used for independent contractors (1099 workers) Provides the contractor's tax information to the hiring company Used by the company to prepare 1099 forms Completed only by the contractor In short, the I-9 is about work eligibility for employees, while the W-9 is about tax information for contractors.