How to Update Form W-4 After Having a Baby

Form W-4, the “Employee’s Withholding Certificate,” is an IRS document employees provide to their employers to determine the correct amount of federal income tax to withhold from a paycheck. This process ensures you pay your income tax gradually throughout the year.

The information on the form, such as your filing status and dependents, impacts your take-home pay. An accurate W-4 helps prevent withholding too little and owing taxes, or withholding too much and waiting for a refund. While required for a new job, you should also update your W-4 after a significant life event.

Information and Decisions for Your New W-4

Having a baby warrants updating your Form W-4, as a new child makes you eligible for the Child Tax Credit, which can lower your tax liability. You will need your baby’s legal name and Social Security Number (SSN). The name on the form must match the name on the Social Security card.

You must wait until you receive the baby’s SSN before submitting an updated W-4. The IRS requires a valid SSN to claim a child for the Child Tax Credit, and filing without it can cause processing issues.

For households where both spouses work, you must coordinate your withholding. The most accurate method is to use the IRS’s online Tax Withholding Estimator, which uses both incomes to recommend how each of you should complete your W-4s.

The second option is to use the worksheet on page three of Form W-4. This method is most accurate when one spouse completes the worksheet and enters the resulting extra withholding amount on the W-4 for the higher-paying job.

Completing Form W-4 Step-by-Step

You can find the current Form W-4 on the IRS website. The form has five steps, but you will only need to complete a few to account for your new child.

In Step 1, enter your personal information, including your name, address, and Social Security Number. You will also select your tax filing status, such as “Married filing jointly” or “Head of household,” that reflects your situation at the end of the year.

Step 2 is for households with multiple jobs or a working spouse. Here, you will apply your decision about coordinating withholding by following the instructions from the IRS Estimator or the form’s worksheet.

Step 3, “Claim Dependents,” is where you account for your new baby. Multiply your number of qualifying children under age 17 by $2,000 and enter the total on line 3. For one new baby, this amount is $2,000. This step reduces your tax withholding to reflect the Child Tax Credit.

Step 4 is for other adjustments, such as other income or deductions. In Step 5, you must sign and date the form to certify its accuracy.

Submitting Your Form and Next Steps

After completing and signing the new Form W-4, submit it to your employer. Many companies require you to hand a physical copy to the human resources or payroll department.

Increasingly, companies use online employee portals for managing tax documents, allowing you to upload or fill out the form digitally. If you are unsure of the correct procedure, contact your HR department for guidance.

After you submit the form, it takes one to two pay cycles for the updated information to be processed and reflected in your paycheck. The exact timing depends on your employer’s payroll schedule.

It is good practice to review your first pay stub after the change takes effect. On the pay stub, locate the line item for “Federal Tax” and you should see that the amount withheld has decreased. Verifying this change confirms that your update was processed correctly.