Updated tables could cause underwithholding

To reflect changes under the TCJA — such as the increase in the standard deduction, suspension of personal exemptions and changes in tax rates and brackets — the IRS updated the tables that indicate how much employers should withhold from their employees’ paychecks for federal income taxes, generally reducing the amount withheld. The new tables might cause some taxpayers, such as those who itemize deductions or are in a two-income household, to not have enough withheld to pay their ultimate tax liabilities under the TCJA.

An IRS calculator can help you more accurately estimate how much should be withheld. (Go to IRS.gov and search “withholding calculator.”) You may find that you need to increase your withholding by filling out a new Form W-4 and submitting it to your employer. You can modify your withholding at any time during the year, or even multiple times within a year.