IRS Form W-4: Employee's Withholding Certificate (2026)

When to complete a new W-4

You'll fill out a W-4 when you start a new job, and you can submit an updated one any time your situation changes. Revisit it after you marry or divorce, have a child, take a second job, or if last year brought a surprise refund or balance due — those are the moments withholding drifts out of line with what you actually owe.

Working through the steps

• Step 1 — Personal information and filing status. Sets your baseline withholding.
• Step 2 — Multiple jobs. Complete this if you work more than one job, or you're married filing jointly and your spouse also works. Skipping it is the most common reason too little tax is withheld.
• Step 3 — Dependents. Claim the child tax credit and credit for other dependents here to reduce withholding.
• Step 4 — Other adjustments. Add other income, deductions beyond the standard deduction, or any extra amount you want withheld each pay period.
• Step 5 — Sign. The form isn't valid until you sign it.

If your taxes are simple — one job, no dependents — you only need Steps 1 and 5.

Common mistakes to avoid

• Ignoring Step 2 with two incomes, which routinely leads to under-withholding and a bill in April.
• Claiming exemption when you don't qualify. You can only claim exempt if you owed no tax last year and expect none this year.
• Forgetting to update it after a major life change.

After you submit it

Your employer keeps the W-4 and adjusts withholding on the next payroll run. Check a paycheck or two later to confirm the amount looks right, and use the IRS Tax Withholding Estimator to fine-tune it.