A payer that must file an information return, such as Form 1099-NEC, 1099-MISC or 1099-K, asks you for a W-9. You give your number when you begin to receive payments a 1099 will report. The form goes to the payer, and you do not send it to the IRS.
Only a US person uses a W-9, including a resident alien or a citizen living abroad. A foreign individual gives Form W-8BEN instead. The number can be a Social Security number, an ITIN or an EIN. For a single-member LLC that is disregarded for tax, your own name goes on line 1 and the LLC’s on line 2.
By signing, you certify under penalties of perjury that the number is correct and that you are a US person. A platform may use its own online tax form instead, when that form is substantially similar to the W-9. Some platforms check the number against IRS records as you submit it.
Without a W-9 that carries your number, the payer may start backup withholding at 24%. It can also start when the IRS notifies the payer that the number you gave is incorrect.
Sources
- IRS, Form W-9 (Rev. March 2024), Request for Taxpayer Identification Number and Certification
- 26 U.S.C. § 3406, Backup withholding
- IRS, Backup withholding
Reviewed and updated September 2026. General information, not advice for your situation.