Fill W-4 online — free, takes 30 seconds
The W-4 tells your employer how much federal income tax to withhold from your paycheck. New job, married, had a kid, picked up a side hustle? Time to update it.
The work happens in your browser — open DevTools → Network and watch: the file is never uploaded to do it.
Who needs it: Every US employee at every new job. Anyone who wants to adjust their withholding after a life change (marriage, kids, second job, big bonus).
Need a blank W-4? Download from the source, then drop it in below.
Why fill it here
- Auto-fill personal info (name, address, SSN, filing status) from your profile.
- Built-in IRS worksheet helpers for dependents and multiple-job adjustments (coming soon).
- Sign and email to HR without leaving your browser.
Fill your W-4 now
W-4 questions, answered
General information, not legal or tax advice
This page is general information about a commonly-used tax form. Tax law is complex and fact-specific — for advice on your return, consult a CPA, enrolled agent, or tax attorney. AttachKit fills the PDF; the IRS holds you responsible for what's on it.
- Does this calculate the right withholding for me?
- AttachKit fills the form. For complex situations (multiple jobs, large itemized deductions, capital gains), use the IRS Tax Withholding Estimator at irs.gov/W4App and copy the values into AttachKit.
- What if I want extra withholding?
- Line 4(c) lets you specify an extra dollar amount per pay period. AttachKit's profile has a field for this if you want it auto-filled too.
More forms: Form 941 · Form 1040 · Form 2553 · Form 2848 · Form 4868 · Browse all 126 forms →
Done filling? Also sign a PDF, convert PDF to Word, Word to PDF — or see AttachKit for accountants.
AttachKit is a private, independent tool for filling and signing PDFs on your own device. It is not a government agency, law firm, or filing service, and is not affiliated with or endorsed by the IRS, USCIS, the U.S. Department of State, or any government body. Forms are provided for convenience — always download the current version and instructions from the official .gov website, and your completed document never leaves your browser.