How to Fax a W-9 or Other Tax Form Online (Without a Fax Machine)

Someone just asked you to fax a W-9 — maybe a client before they can pay your invoice, or a vendor onboarding you into their system. You have not owned a fax machine in years. The good news: you can fax a W-9 or other tax form online from your browser, no fax machine or app install needed. Here is how we recommend doing it safely.

Why do people ask for a W-9 by fax?

When you start working with a new client or vendor, their accounting team often needs a completed Form W-9 to set you up as a payee. It contains your legal name, address, entity type, and TIN — the information they need to issue your 1099 at year end.

One important detail: a W-9 goes to the requester — the company or person paying you — not to the IRS. The fax number you need is the requester's, and you should always confirm it directly with them.

Step 1: Get the current form from IRS.gov

Before you fax anything, download the current version of the form directly from IRS.gov — the requester may reject an outdated revision. Search IRS.gov for "W-9" and download the latest PDF.

The same rule applies to other forms, such as 8821, 2848, or SS-4: download the current version from IRS.gov and confirm the correct fax number on that form's instructions page. We list no fax numbers here because the only reliable source is the current IRS.gov page.

Step 2: Fill and sign the form

You can fill most IRS PDFs in a PDF editor. At Unlimited Faxing, a PDF editor and e-signature tool are included in the same account, so you can complete the form, sign it, and fax it without leaving your browser. One caveat: check with the requester that they accept e-signatures. If they need a wet-ink signature, print, sign, and scan it back in — the iPhone Files app does this in seconds (Files > three dots > Scan Documents).

Step 3: Protect your TIN

Your Social Security number or EIN is sensitive, and a misdirected fax can expose it. Take three precautions:

1. Confirm the fax number through a trusted source. Do not rely solely on an email that could be spoofed — verify it with the requester by phone or through contact details you already had on file.
2. Use a minimal cover sheet with no SSN. Our free fax cover sheet maker requires no account and does not save what you type.
3. Verify the recipient — confirm the fax arrived and was legible.

Step 4: Send the fax

Sending a W-9 with Unlimited Faxing takes a few minutes:

1. Open Unlimited Faxing in your browser and sign in (it works in iPhone Safari; on a free account, confirm your email first).
2. Open Send a fax and upload your completed, signed PDF.
3. Add the confirmed recipient fax number and your minimal cover sheet.
4. Review the pages and send.

Your plan options:

• Free account — $0. 5 fax pages per month, sent from a shared number. No PayPal or card required — just confirm your email to send. A W-9 plus a one-page cover sheet fits comfortably. A free account cannot receive faxes on your own number.
• Pro — $19/mo billed annually ($228/yr) or $22.80 month to month. 500 pages, 3 fax numbers of your own, and 100 e-signatures per month. A 7-day free trial is approved with PayPal — cancel before it ends, or it renews automatically. The better choice if you will exchange tax documents regularly.

See full details on our pricing page.

Step 5: Confirm delivery

After sending, your fax list shows the delivery status of every fax. If a fax fails, it lands in your Outbox, where you can enable automatic retries or resend it yourself — useful when a recipient's line is busy.

Faxing other tax forms (8821, 2848, SS-4)

Some IRS forms are faxed directly to the IRS — for example, 8821 (tax information authorization), 2848 (power of attorney), and SS-4 (application for an EIN). For these:

• Download the current form and instructions from IRS.gov.
• Confirm the current fax number in the instructions — never use a number from an old form or a blog.
• Check with the requester or a tax professional that fax is the accepted submission method.

We do not give tax advice — confirm the fax number and whether fax is accepted on IRS.gov or with the requester before sending.

Receiving replies by fax

If the requester or the IRS wants to fax something back to you — a stamped copy, a transcript, an acknowledgment — you need a fax number of your own. A free account sends only from a shared number, so start a Pro trial. Incoming faxes appear in your fax list and can be emailed to you with fax-to-email.

Faxing a tax form online beats finding a fax machine. Get the current form from IRS.gov, confirm the number, add a minimal cover sheet, and send — then check the delivery status and follow up with the requester. For more help, browse our guides.

Questions

Related guides

• Online fax for tax preparers
• Fax cover sheet guide
• E-signature plus online fax
• Free fax cover sheet maker