How to Fill Out Your W-4

What Is the W-4?

The W-4 is the form you give your employer that determines how much federal income tax to withhold from each paycheck. Getting it right means you won't owe a big bill at tax time or give the IRS an interest-free loan via an oversized refund.

The form was redesigned in 2020. It no longer uses "allowances" (the old system where you claimed 0, 1, 2, etc.). Instead, you enter dollar amounts for dependents, other income, deductions, and extra withholding.

The 5 Steps, Explained

Step 1: Personal Information (Required)

Enter your name, address, Social Security number, and filing status. Your filing status is the most important choice here:

• Single or Married Filing Separately: Choose this if you're unmarried, or married but filing separate returns
• Married Filing Jointly: Usually the best option for married couples (lower tax rates and higher standard deduction)
• Head of Household: If you're unmarried and pay more than half the cost of keeping up a home for a qualifying person

Step 2: Multiple Jobs (If Applicable)

Complete this step only if you have more than one job simultaneously, or if you're married filing jointly and both spouses work. You have three options:

1. Use the IRS Tax Withholding Estimator (most accurate but time-consuming)
2. Use the Multiple Jobs Worksheet on page 3 of the W-4
3. Check the box in Step 2(c) if there are only two jobs with similar pay (simplest option)

If you don't complete Step 2 when you should, you'll likely underwithhold and owe a balance at tax time. This is the most common W-4 mistake for dual-income households.

Step 3: Dependents

Claim tax credits for your dependents:

• Children under 17: $2,000 per child (multiply number of children by $2,000)
• Other dependents: $500 per dependent (elderly parents, adult children, etc.)

Enter the total dollar amount. This reduces your withholding to account for the credits you'll claim on your tax return.

Step 4: Other Adjustments (Optional)

• 4(a) Other income: Enter income from non-job sources (interest, dividends, retirement) that isn't subject to withholding. This increases your withholding to cover the tax on this income.
• 4(b) Deductions: If you plan to itemize or claim deductions beyond the standard deduction, enter the excess amount here. This decreases your withholding.
• 4(c) Extra withholding: Enter a dollar amount to withhold from each paycheck beyond the normal calculation. Use this to fine-tune if other steps don't get you close enough.

Step 5: Sign and Date

Sign the form and give it to your employer. Your employer cannot refuse a properly completed W-4.

Common Scenarios

Single, one job, no dependents

The simplest case. Complete Step 1, skip Steps 2–4, sign Step 5. The default withholding based on your filing status and salary will be close to your actual tax liability.

Married, both spouses work

This is where most people get tripped up. If both spouses earn similar amounts, the easiest approach is for both to check the box in Step 2(c). If incomes are very different, use the W-4 calculator for more accurate results.

Single parent, head of household

Select "Head of Household" in Step 1 (this gives you a larger standard deduction and more favorable brackets). In Step 3, enter $2,000 per child under 17. This often results in a refund, which you can adjust by reducing the Step 3 amount if you prefer even withholding.

When to Update Your W-4

• New job: You'll fill out a new W-4 for every employer
• Marriage or divorce: Your filing status and potentially your bracket changes
• Having a child: New dependent credits in Step 3
• Buying a home: Mortgage interest may mean you should itemize (Step 4b)
• Side income: Add it in Step 4(a) to avoid a tax bill
• Large refund or balance due: Your current W-4 is off — adjust it