When a U.S. payer asks for a Form W-9, an ITIN holder writes that nine-digit number in the taxpayer identification number box exactly where a Social Security Number would go. The payer keeps the W-9 on file and uses your ITIN to file a Form 1099 reporting what they paid you, so using an ITIN on Form W-9 and 1099 works the same way an SSN would. The tricky part is not the number itself. It’s making sure you’re the person who should be handing over a W-9 in the first place, and that the ITIN on it is entered cleanly enough for the IRS to match the 1099 to your return.
W-9 or W-8BEN: Which Form You Owe the Payer
Having an ITIN does not automatically mean you file a W-9. The right form depends on whether you are a U.S. person for tax purposes.
- File Form W-9 if you are a U.S. citizen or a resident alien. Resident aliens include green card holders and anyone who meets the substantial presence test.
- File Form W-8BEN if you are a nonresident alien receiving U.S.-source income such as dividends, interest, rents, or royalties.1Internal Revenue Service. Instructions for Form W-8BEN
The substantial presence test asks whether you were physically in the United States for at least 31 days this year and 183 days across a three-year weighted count (all of this year’s days, one-third of last year’s, one-sixth of the year before).2Internal Revenue Service. Substantial Presence Test If you hit 183, you’re a resident alien and the correct form is W-9. If your status changes mid-year, tell the payer within 30 days and swap the form.1Internal Revenue Service. Instructions for Form W-8BEN
Submitting the wrong form has real cost. A nonresident alien who hands over a W-9 loses the ability to claim tax treaty benefits that could reduce or eliminate withholding. A resident alien who submits a W-8BEN can end up with the default 30% withholding rate for foreign persons rather than the 24% backup rate that only applies when something goes wrong on a W-9.3Office of the Law Revision Counsel. 26 U.S. Code 1441 – Withholding of Tax on Nonresident Aliens Nonresident aliens claiming a treaty rate on Form W-8BEN enter the ITIN on line 5, unless they list a foreign tax identification number on line 6. Without a valid W-8BEN on file, the payer must withhold at 30%.1Internal Revenue Service. Instructions for Form W-8BEN
Filling Out Form W-9 With Your ITIN
Once you’ve confirmed the W-9 is the right form, the entries themselves are short but unforgiving. The IRS uses the number and name on this form to match the payer’s 1099 to whatever you report on your tax return, so anything that doesn’t line up creates problems later.4Internal Revenue Service. Form W-9 – Request for Taxpayer Identification Number and Certification
- Line 1: your legal name exactly as it appears in IRS records for that ITIN.
- Line 2: a business name, if you use one that differs from line 1.
- Federal tax classification: individual, sole proprietor, LLC, and so on. Check one.
- Part I: enter the nine-digit ITIN in the taxpayer identification number box. An ITIN always begins with 9.5Internal Revenue Service. Instructions for Form W-7
- Part II: sign and date. The signature certifies under penalty of perjury that the number is correct and that you are not subject to backup withholding. If the IRS has previously notified you that you’re subject to backup withholding for failing to report interest or dividends, cross out item 2 before signing.4Internal Revenue Service. Form W-9 – Request for Taxpayer Identification Number and Certification
The W-9 stays with the payer. Don’t send it to the IRS.
How Your ITIN Appears on the 1099
After the tax year closes, the payer uses the information from your W-9 to prepare a 1099 if the payments reach the reporting threshold. Your ITIN goes in the recipient’s TIN box on the form, in the same slot a Social Security Number would occupy. You receive a copy; the IRS receives a copy.
Two forms cover most situations for an individual paid by a U.S. business:
- Form 1099-NEC is required when a business pays $2,000 or more to a non-employee for services during the calendar year. The threshold rose from $600 for payments made after December 31, 2025, and will be adjusted for inflation starting in 2027.6Internal Revenue Service. Form 1099-NEC and Independent Contractors
- Form 1099-MISC is required when a business pays $600 or more in rent, royalties, prizes, medical and health care payments, or other miscellaneous income.7Internal Revenue Service. About Form 1099-MISC, Miscellaneous Information
When your 1099 arrives, check that the ITIN and your name match what you put on the W-9. Mismatches are the most common reason the IRS sends a notice, and the fix is easier before you file your return than after.
What Happens If the ITIN Is Missing or Wrong
If you don’t return a W-9, return one without a TIN, or provide a number the IRS tells the payer is incorrect, the payer must begin backup withholding at a flat 24% on reportable payments.8Office of the Law Revision Counsel. 26 U.S.C. 3406 The withheld amount goes to the IRS and gets credited against your eventual tax liability when you file.
This is not a penalty in the technical sense, but it ties up nearly a quarter of your income until you file a return and claim the credit. Providing a correct ITIN on the W-9 the first time avoids it entirely. If withholding has already started, you recover the money by filing a federal return and claiming the withheld amount as a credit.
Expired ITINs and Information Returns
An ITIN that hasn’t been used on a federal tax return for three consecutive years expires on December 31 of that third year. For W-9 and 1099 purposes, this matters less than you might think: an expired ITIN can still be used on information returns without renewal. Renewal is only required when the ITIN will appear on a federal income tax return you file.9Internal Revenue Service. How to Renew an ITIN
So a payer can accept your W-9 and file a 1099 using an ITIN that has technically expired. But when you go to file your own return and report that 1099 income, you’ll need to renew first using Form W-7, checking the “Renew an existing ITIN” box and providing the same identity documentation you supplied originally. If your legal name has changed, include documentation of the change such as a marriage certificate or court order.