What Is Form W-9?

Form W-9 is used by businesses to collect the taxpayer identification number (TIN) of contractors, freelancers, and others they pay. When you do work for someone as an independent contractor, they'll ask you to fill out a W-9. Your information from the W-9 is used to prepare a Form 1099-NEC at year-end. If you don't provide a W-9, the payer must withhold 24% "backup withholding" from payments to you. W-9s are not sent to the IRS — they stay with the business requesting them.