How to Fax IRS Form W-9 — Provide Your Taxpayer ID to a Requester
Form W-9 is how an independent contractor, freelancer, vendor, or other payee gives their correct taxpayer identification number and certification to a business that will pay them. The requesting business uses it to prepare information returns — most often a 1099 — reporting what they paid. The signer certifies that the taxpayer identification number provided is correct and that they are not subject to backup withholding. Unlike most IRS forms, a completed W-9 is not sent to the IRS at all; it goes to the person or company that asked for it.
Why this form is faxed
A business often needs a signed W-9 on file before it can issue a payment or year-end 1099, and faxing gets the certified form to the requester quickly as a fixed document. Because a W-9 carries a full taxpayer identification number, sending it as a faxed page keeps it out of ordinary email and gives the sender a dated record that it was delivered. It is a simple, verifiable way to satisfy a payer's onboarding requirement.
Where it goes
A W-9 does not go to the IRS — it goes only to the business, client, or financial institution that requested it, so the correct destination is the fax number that specific requester gives you. Confirm the number directly with the party who asked for the form rather than guessing, and be cautious about any unexpected request, since a W-9 should only go to a payer you actually have a relationship with.
How to fax IRS Form W-9 (Request for Taxpayer Identification Number and Certification)
- 1Enter your name and business name exactly as they appear on your tax filings, and select the correct federal tax classification
- 2Provide your taxpayer identification number — a Social Security number for individuals, or an EIN for a business
- 3Sign and date the certification confirming the number is correct and your backup-withholding status
- 4Confirm the fax number directly with the client or business that requested the W-9
- 5Log in to Send FAX Mail, upload the signed PDF, enter the requester's confirmed number, and send
- 6Save the transmission confirmation as your record of when and to whom you provided the form
Handling sensitive information
A W-9 exposes a full Social Security or employer identification number tied to your name and address, which is exactly what's needed to open fraudulent accounts or file a false return in your name. Send it only to a requester you can verify has a legitimate reason to pay you, and treat any surprise W-9 request as a possible phishing attempt before transmitting your identifying number.
Faxing IRS Form W-9 (Request for Taxpayer Identification Number and Certification) — FAQ
No. The W-9 goes only to the business or institution that requested it — they keep it on file and use the information to report payments to you. You never file a W-9 with the IRS yourself. That's a key difference from most tax forms, which are submitted to the agency directly.
Individuals and sole proprietors typically use their Social Security number, while a business entity generally uses its employer identification number. If you have an EIN, using it can keep your SSN off the form entirely. Match the number to how you file and to the name you entered at the top.
Be skeptical. A legitimate W-9 request comes from a party that is actually going to pay you, so verify who's asking and why before sending your identifying number. Scammers use fake W-9 requests to harvest Social Security numbers. Confirm the relationship and the fax number directly before you transmit anything.
Your signature certifies that the taxpayer identification number you gave is correct and states your backup-withholding status, among other attestations. Providing a wrong number or a false certification can carry consequences. Double-check the number against your records before signing and faxing the form.
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