How should I fill out my W-4?

Concerns & risks

You started a new job and HR handed you a W-4. You have no idea what to put.

Wrong W-4 = surprise tax bill or tiny paychecks.

Causes & evidence

Your W-4 tells your employer how much to withhold. See tax withholding.

What to do

1. Fill out step 1 (personal info).
2. Do steps 2-4 only if they apply (multiple jobs, dependents, other income).
3. Use the IRS Tax Withholding Estimator.
4. Sign and give it to your employer.

Common mistakes: Common mistakes: guessing, or copying what a coworker did. Use the IRS Tax Withholding Estimator. Update your W-4 after life changes like marriage, a new baby or a second job. Check your pay stub after the change to make sure the withholding looks right. If you have more than one job, or you and your spouse both work, the W-4 has a step for that; skipping it is a common reason people owe at tax time. You can submit a new W-4 to your employer any time during the year, so it's not a one-shot decision. Check the result on your next pay stub and again midyear.

Speed Man tip: Recheck after big life changes.

Wrap-up: Fill only steps that apply. Use the IRS estimator. Update after life changes.