Information from IRS.gov

Several factors that could affect potential refunds or taxes you may owe in 2018. Reviewing the amount of taxes withheld can help avoid having too much or too little federal income tax taken from paychecks. Having the correct amount taken out helps to move taxpayers closer to a zero balance at the end of the year when a tax return is filed, which means no taxes owed or refund due.

During the year, changes sometimes occur — such as marital status, that impacts exemptions, adjustments or credits that can be claimed on a tax return. If changes happened, give your employer a new Form W-4 to change their withholding status or number of allowances.

Employers use the form to figure the amount of federal income tax to be withheld from pay. Making these changes in the late summer or early fall can give taxpayers enough time to adjust their withholdings before the tax year ends in December.

The withholding review takes on even more importance now that federal law requires the IRS to hold refunds a few weeks for some early filers claiming the Earned Income Tax Credit and the Additional Child Tax Credit.