The IRS announced today, during the government shutdown, that it will waive the estimated tax penalty for many taxpayers whose 2018 federal income tax withholding and estimated tax payments fell short of their total tax liability for the year.

The Tax Code applies a penalty (referred to as an addition to tax) in the case of an underpayment of estimated tax. Although the addition to tax is computed in the same manner as interest, it is a penalty and not interest. Like other penalties, this addition to tax is not deductible as an expense. The addition to tax is computed at the underpayment rate (currently 6%). 

Because the U.S. tax system is pay-as-you-go, taxpayers are required, by law, to pay most of their tax obligation during the year, rather than at the end of the year. This can be done by either having tax withheld from paychecks or pension payments, or by making estimated tax payments.
 
Usually, a penalty applies at tax filing if too little is paid during the year. Normally, the penalty would not apply for 2018 if tax payments during the year met one of the following tests:

• The person's tax payments were at least 90 percent of the tax liability for 2018 or
• The person's tax payments were at least 100 percent of the prior year's tax liability, in this case from 2017. However, the 100 percent threshold is increased to 110 percent if a taxpayer's adjusted gross income is more than $150,000, or $75,000 if married and filing a separate return.

The IRS is generally waiving the penalty for any taxpayer who paid at least 85 percent of their total tax liability during the year through federal income tax withholding, quarterly estimated tax payments or a combination of the two. The usual percentage threshold is 90 percent to avoid a penalty. This relief is designed to help taxpayers who were unable to properly adjust their withholding and estimated tax payments to reflect an array of changes under the Tax Cuts and Jobs Act (TCJA), the far-reaching tax reform law enacted in December 2017. The updated federal tax withholding tables, released in early 2018, largely reflected the lower tax rates and the increased standard deduction brought about by the new law. This generally meant taxpayers had less tax withheld in 2018 and saw more in their paychecks. However, the withholding tables couldn't fully factor in other changes, such as the suspension of dependency exemptions and reduced itemized deductions. As a result, some taxpayers could have paid too little tax during the year, if they did not submit a properly-revised W-4 withholding form to their employer or increase their estimated tax payments.

 To help taxpayers get their withholding right in 2019, an updated version of the agency's online Withholding Calculator is now available. With tax season starting January 28, the IRS reminds taxpayers it's never too early to get ready for the tax-filing season ahead. While it's a good idea any year, starting early in 2019 is particularly important as most tax filers adjust to the revised tax rates, deductions and credits.