If you pay quarterly estimated tax payments, you may want to revisit the amount you pay.

The Tax Cuts and Jobs Act changed the way most taxpayers calculate their tax. These taxpayers include those with substantial income not subject to withholding, such as small business owners and self-employed individuals. The tax reform changes include:

• Revised tax rates and brackets
• New and revised business deductions
• Limiting or discontinuing deductions
• Increasing the standard deduction
• Removing personal exemptions
• Increasing the child tax credit

As a result of these changes, many taxpayers may need to raise or lower the amount of tax they pay each quarter through estimated taxes.

Alternatively, many taxpayers who receive income not subject to withholding, but who also receive income as an employee, may be able to avoid the requirement to make estimated tax payments by having more tax taken out of their pay. These taxpayers can use the Withholding Calculator on IRS.gov to perform a Paycheck Checkup. Doing so now may help avoid an unexpected year-end tax bill and possibly a penalty in the future. 

Taxpayers with more complex situations might need to use IRS Publication 505, Tax Withholding and Estimated Tax, instead.  This includes people who owe self-employment tax, the alternative minimum tax, or tax on unearned income from dependents, and people with capital gains or dividends.

Note that the IRS is waiving 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. 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. The IRS will generally waive 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.

For more information about the penalty and requesting the waiver, see IRS Form 2210 and its instructions.