How to Fax a W-9 Form Securely | SecurelyFax
Form W-9 is the payee identification form your client, customer, or vendor asks for so they can issue you a 1099 or set up payment. It is not filed with the IRS — it goes to the requester. Fax is one of the safer ways to deliver it because it avoids attaching your SSN or EIN to an email, and SecurelyFax sends from email, browser upload, or a phone scan with a delivery confirmation you keep for your records.
What W-9 is for (and what it isn't)
W-9 is the Request for Taxpayer Identification Number and Certification — you give it to a person or business that pays you, so they have your name and TIN (SSN or EIN) on file. It is not a tax return. Common scenarios: a new client onboarding you as a contractor, a property-management company collecting tenant tax info, a brokerage opening an account, a customer setting up vendor payments.
Why fax (instead of email)
Form W-9 contains either a Social Security Number or an EIN. Sending a document with an SSN on it through unencrypted email is a routine identity-theft setup — the requester's inbox is a frequent target, and old W-9 attachments live in archived emails forever. Fax is a closed point-to-point delivery with a confirmation receipt. Many requesters explicitly publish a fax number for exactly this reason.
How to fax a W-9 through SecurelyFax
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Get a current W-9 from IRS.govThe W-9 is updated periodically. Always use the latest version, not an older copy from your downloads folder.
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Fill it out and signName, business name (if any), entity type, address, TIN (SSN or EIN), and signature.
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Confirm the requester's destination fax numberAsk the requester (or check their vendor-onboarding portal). The IRS does not publish a W-9 fax destination because W-9 doesn't go to the IRS.
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Add a cover sheet with a confidentiality noticeStandard confidentiality language helps if the W-9 reaches the wrong recipient. SecurelyFax can generate the cover sheet for you.
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Send through SecurelyFaxEmail the signed W-9, upload it in your browser, or photograph the signed form with your phone.
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Save the delivery confirmationKeep the SecurelyFax receipt with your client / engagement file. If a 1099 is later missing or wrong, the receipt proves you delivered the W-9.
What to NOT do with a W-9
Don't post it in a project-management tool. Don't email it without encryption. Don't text it. Don't put it in a shared cloud folder that other vendors can see. The TIN on a W-9 is exactly the data identity thieves want — handle it like a credit card number, not like a contract.
SecurelyFax sends the document to the destination number you provide and returns a delivery confirmation. We can't tell you the requester's correct fax number — confirm it with them. For any W-9 you send, save the confirmation receipt: it's evidence that the requester received your TIN, which matters at 1099 reconciliation time.
Frequently asked questions
Do I fax my W-9 to the IRS?
No. Form W-9 goes to the person or business that requested it — typically a payer, client, vendor, or financial institution. The IRS does not collect W-9s directly.
Which fax number do I use?
The destination is whatever number the requester gives you. Ask if it's not on their onboarding form or portal.
Is fax safer than email for a W-9?
Usually yes. Fax is a point-to-point delivery with a confirmation receipt; unencrypted email leaves a permanent record of your SSN in inboxes you don't control.
Do I need a fax machine?
No. SecurelyFax sends from email, browser upload, or phone scan, with a generated cover sheet that can include a confidentiality notice.
Should I include a confidentiality notice?
Yes — recommended on any fax containing a TIN. The standard one-paragraph notice asks the recipient to destroy the document and notify the sender if it was received in error.
Last reviewed: 2026-05-30