How to Fill Out Federal Tax Withholding

The United States operates on a pay-as-you-go tax system, meaning you must pay income tax as you earn it. For most employees, this is done through federal tax withholding, where an employer deducts taxes from each paycheck. The primary document for this is the IRS Form W-4, Employee’s Withholding Certificate. Properly completing this form helps align your withholding with your annual tax liability, avoiding a large tax bill or an excessive refund.

Information and Tools for Form W-4

Before filling out Form W-4, gather your most recent pay stubs, especially if you have multiple jobs or are married filing jointly with a working spouse. You will also need the most current version of the form from the IRS website.

A significant part of the form involves accounting for dependents. A dependent must be either a “Qualifying Child” or a “Qualifying Relative,” each with specific IRS tests. A qualifying child must meet relationship, age, residency, and support tests, while a qualifying relative has criteria that include an income limit of under $5,200 for 2025.

You will also need figures for other adjustments, such as non-job income from interest or dividends, or deductions you expect to claim beyond the standard deduction. The most accurate way to determine these figures is by using the IRS Tax Withholding Estimator, an online tool that provides specific recommendations for what to enter on the form.

A Step-by-Step Guide to Completing Form W-4

With your financial information gathered, you can proceed with filling out the Form W-4. The form is divided into five steps, though not all may apply to your circumstances.

Step 1: Enter Personal Information

This step requires your full name, Social Security number, and address. You must also select your anticipated tax filing status: “Single or Married filing separately,” “Married filing jointly or Qualifying surviving spouse,” or “Head of household.” Your choice of filing status determines the standard deduction and tax rates used to calculate your withholding.

Step 2: Multiple Jobs or Spouse Works

This step is for employees who hold more than one job or are married filing jointly with a working spouse. The most accurate method is to use the results from the IRS Tax Withholding Estimator. Alternatively, you can use the “Multiple Jobs Worksheet” provided on page 3 of the form and enter the resulting figure in Step 4(c). A third option, for households with only two jobs, involves checking a box in this step on the W-4s for both jobs.

Step 3: Claim Dependents

If you have dependents, you will multiply the number of qualifying children under age 17 by $2,000 and the number of other dependents by $500. You then add these amounts and enter the total on line 3. This amount directly reduces the tax withheld from your pay, reflecting the tax credits you expect to claim.

Step 4: Other Adjustments

This optional step allows for fine-tuning your withholding. In Step 4(a), you can report other non-job income not subject to withholding to increase the tax withheld. In Step 4(b), you can account for deductions other than the standard deduction. Finally, Step 4(c) is for any extra tax you want withheld from each paycheck, which might include an amount from the Multiple Jobs Worksheet.

Step 5: Sign and Date

The final step is to sign and date the form. Your signature certifies that the information provided is correct. The Form W-4 is not considered valid without your signature, and once signed, you submit the completed form to your employer.

Submitting the Form and Post-Filing Actions

After you have completed and signed your Form W-4, you must submit it to your employer. Many companies utilize online payroll systems that allow you to enter your W-4 information electronically. Your employer is required to implement the changes to your withholding promptly, usually within one to two pay cycles.

It is a good practice to review your first pay stub issued after submitting the new form. Check the amount of federal income tax withheld to confirm it reflects the changes you intended.

You should revisit your Form W-4 whenever you experience a significant life event that could alter your tax situation, such as getting married, having a child, or a change in employment. The IRS recommends reviewing your withholding at least once a year to ensure its accuracy.