Fill IRS Form W-9 Online

Form W-9, the IRS's "Request for Taxpayer Identification Number and Certification," is the form every US business asks new contractors, freelancers, and vendors to complete before sending them any money. A company that pays you $600 or more in a year needs your tax identification number on file so they can issue you (and the IRS) a 1099-NEC at year-end. The W-9 is how they collect that number. The form itself is short — one page, eight numbered fields, a signature, and a date — but mistakes on it can delay your first invoice or trigger backup withholding at 24%, so it's worth filling out carefully.

FormatFuse opens the official 2026 IRS W-9 PDF, lets you type directly into every field, and saves the completed file with the values flattened so the recipient can't accidentally edit them. The form, the values you type, your social security number, and your signature all stay on your device — there's no upload, no signup, and no log of what you filled in. That matters because a W-9 contains the exact PII you should never paste into a free online form filler that quietly mirrors your inputs to a server: your full legal name, your address, and either your SSN or EIN.

If you're a single-person LLC, the correct tax classification is almost always "Individual/sole proprietor or single-member LLC" unless you've filed Form 8832 or Form 2553 to elect S-corp or C-corp tax treatment — most freelancers haven't. The exempt-payee fields (lines 4) are usually left blank; they apply to specific entities like banks, government agencies, and tax-exempt organizations. The certification block at the bottom (Part II) is where you sign attesting that the TIN you provided is correct, that you're not subject to backup withholding, and that you're a US person. Sign with your typed name in the browser or use the signature pad if you want a handwritten look.

After you download the filled W-9, return it to the requester through whatever channel they specified — usually an upload portal on their vendor onboarding software (Bill.com, Tipalti, Ramp), or a secure encrypted email if they're old-school. Do not email an unencrypted W-9 attachment to a generic inbox, and never post one to a Slack channel: your SSN is the most valuable single piece of identity-theft fuel that exists, and a leaked W-9 is the express lane to fraudulent tax returns and credit applications in your name. If a requester asks you to fax it, that's actually fine — fax over phone lines is point-to-point. The W-9 itself never goes to the IRS; the requester keeps it on file for at least four years after the related 1099 is filed.