How to fill out a W-4, step by step

Draft, figures being verified: Juliette or Fred checks this guide against the 2026 Form W-4 before it goes live.

What to have in front of you

Your most recent pay stub, your spouse's too if you file jointly, and last year's tax return. It takes about ten minutes.

Step 1: your details and filing status

Your name, address and Social Security number, and one of three boxes for your filing status. The box sets the starting point for the rest of the form.

If you're married and file a joint return, tick married filing jointly even if only one of you works.

Step 2: more than one job, or a spouse who works

The withholding tables assume each job is your only income. If you have two jobs, or you and your spouse both work, each employer takes out too little unless you complete this step. It's the most common reason couples owe in April.

There are three ways to do it: tick the box in Step 2(c) on both W-4s if the two jobs pay about the same, use the IRS Tax Withholding Estimator, or fill in the Multiple Jobs Worksheet on the form. Use one of them.

Step 3: dependents

This step applies if your income is $200,000 or less, or $400,000 or less if you're married filing jointly.

Multiply the number of qualifying children under 17 by $2,200, and the number of other dependents by $500, then add the two together.

Only one of you should claim the children if you're married and both work, usually the higher earner. Claiming them on both W-4s is the second most common reason for a bill in April.

Step 4: other adjustments

These are optional.

4(a) is for income that has no tax withheld, such as interest, dividends or a side business, so the tax on it comes out of your pay instead of arriving as a bill.

4(b) is for deductions. The 2026 form's Deductions Worksheet has new lines for the deductions added by the 2025 tax law: qualified tips up to $25,000, qualified overtime up to $12,500 ($25,000 if you're married filing jointly), interest on a qualifying car loan up to $10,000, and $6,000 for each person aged 65 or over.

4(c) is for extra tax taken out each pay period. It's the simplest way to cover a shortfall from a bonus, a second job or a balance due last year.

If you qualify to be exempt from withholding, the 2026 form has a checkbox for it below Step 4(c).

Step 5: sign it and hand it in

Sign and date it, and give it to whoever runs payroll. Your employer has to start using it within about 30 days, and most do it from the next pay run. Keep a copy.

When something in your life changes

Marriage or divorce, a new child, a new job for either of you, starting a side business, buying a house, or a large refund or bill last year. You can hand in a new W-4 as often as you like, and the old one stays in force until you do.

The two mistakes we fix most often

Both spouses claiming the children, and nobody completing Step 2. Between them, they explain most of the calls we get in April asking why someone owes.

Check the numbers before you hand it in

Our paycheck calculator shows how a W-4 choice changes your take-home pay. The IRS Tax Withholding Estimator goes further and tells you what to write in Step 4(c).

Open the paycheck calculatorIRS Tax Withholding Estimator