How to Fill Out a W-4 — Step by Step

Form W-4 (Employee's Withholding Certificate) tells your employer how much federal income tax to pull from each paycheck. You hand it to your employer's payroll — not the IRS — when you start a job and again whenever your situation changes. The current form (redesigned in 2020) has five steps, but only two are required for most people. This guide walks them in order. Ready to fill one? Use our free W-4 filler — it runs in your browser and never uploads your SSN.

Step 1 — Personal information (required)

Your name, address, Social Security Number and filing status: single or married filing separately, married filing jointly, or head of household. The filing status drives which standard deduction and tax brackets your employer uses for withholding — pick it carefully, it's not just a label.

Step 2 — Multiple jobs or a working spouse

Fill this step only if you hold more than one job, or your spouse works. When two incomes exist, each employer withholds as if theirs were the only income unless you correct for it — that's the classic recipe for an April tax bill. You have three options:

• The IRS Tax Withholding Estimator (irs.gov) — the most accurate route; it produces numbers you can enter directly into Steps 3 and 4.
• The worksheet on page 3 of the form — the paper alternative.
• The checkbox in 2(c) — only when there are exactly two jobs in the household with roughly similar pay.

Skipping Step 2 when it applies is the single most common cause of under-withholding — it affects married couples with two earners far more often than people expect.

Step 3 — Dependents

If your income is within the form's limits, claim the child tax credit and the credit for other dependents here: multiply your qualifying children by the per-child amount printed on the form and add other dependents at their listed amount. This step reduces withholding — if your household income is higher, you may not qualify for the credits at all.

Step 4 — Other adjustments (optional)

Three independent knobs, all optional:

• 4(a) — Other income. Income not from jobs: interest, dividends, retirement income, a side business without withholding. Reporting it here spreads the tax across paychecks instead of a surprise at filing.
• 4(b) — Deductions. Only if you expect to itemize above the standard deduction — the worksheet on page 3 helps you compute the difference.
• 4(c) — Extra withholding. A fixed extra amount per paycheck. If you consistently owe in April, this is the cleanest fix; if you consistently get a large refund, removing it puts that money back in your paychecks.

Step 5 — Sign and date (required)

The form is invalid without a signature. An electronic signature is fine for payroll purposes — our W-4 tool includes a signature pad and flattens the finished PDF.

Writing “exempt” — the high-stakes line

The exempt checkbox is only for people who owed no federal income tax last year and expect to owe none this year. If that genuinely describes you, write “Exempt” under Step 4 and skip Steps 2–4. If it doesn't, writing “exempt” means no withholding at all — and underpayment penalties later.

The mistakes that actually bite

• Looking for “allowances”. The pre-2020 form used allowances; the current one works in dollar amounts. Any tutorial telling you to “claim 0 or 1” is outdated.
• Ignoring Step 2 with two incomes. Each employer withholds on half the story; the combined tax comes due at filing.
• Set-and-forget. Marriage, divorce, a new child, a second job, a spouse starting or stopping work — resubmit the W-4 after each. There's no limit on how often.
• Treating a big refund as a win. It's an interest-free loan to the Treasury. Adjust Step 4 instead.
• Sending it to the IRS. The W-4 goes to your employer's payroll only.

Keep your SSN off third-party servers

The W-4 contains your SSN and filing status — exactly what payroll portals and HR inboxes shouldn't casually hold on outside servers. Fill and sign the form locally with our W-4 tool: the template loads in your browser, you complete it offline if you like, and the flattened PDF with wiped metadata lands on your device.

Fill out your W-4 now — free, no upload

This guide is general information, not tax advice. For your specific situation, use the IRS Tax Withholding Estimator or consult a tax professional.