How to Fill Out a W-4 Form (2025)

The W-4 Employee's Withholding Certificate tells your employer how much federal income tax to withhold from each paycheck. Fill it out wrong and you'll either owe a surprise bill in April or give the IRS an interest-free loan all year. Here's how to get it right.

When to Fill Out a W-4

• Starting a new job
• Getting married or divorced
• Having a child
• Taking on a second job
• Your tax situation changed significantly

The Five Steps on the 2025 W-4

Step 1: Personal Information (Required)

Enter your name, address, SSN, and filing status. This is the one step everyone must complete.

Step 2: Multiple Jobs or Spouse Works (Optional but Important)

If you have more than one job, or if you're married and your spouse also works, complete this step. Without it, each employer withholds as if your job is your only income — and you'll likely owe at filing time because your combined income pushes you into higher brackets.

Options: use the IRS withholding estimator online, or check the box that triggers higher withholding from this job.

Step 3: Claim Dependents (Optional)

If your total income is $200,000 or less ($400,000 or less if MFJ), you can claim child and dependent care credits here. This reduces your withholding to account for the credits you'll claim when you file.

• Children under 17: $2,000 per child
• Other dependents: $500 per dependent

Step 4: Other Adjustments (Optional)

Three sub-items:

• 4(a) Other income: Freelance income, investment income, or other sources not subject to withholding — add it here so extra tax is withheld
• 4(b) Deductions: If you itemize and your deductions exceed the standard deduction, enter the excess to reduce withholding
• 4(c) Extra withholding: A flat extra dollar amount per paycheck — useful if you want to avoid underpayment

Step 5: Sign and Date (Required)

Sign the form. Your employer is not required to withhold anything without a signature.

What Happens If You Don't Submit a W-4?

Your employer will default to the standard withholding for a single filer with no adjustments. This is often fine, but may result in under-withholding if you have a complex situation.

State Withholding Forms

Most states have their own withholding certificate (similar to the W-4). You'll typically fill these out alongside the federal W-4 when you start a job or update your information.