Whether or not you owed taxes or received a refund last year you check your tax withholding due to the massive changes brought about by the Tax Cuts and Jobs Act of 2017. Owing tax at the end of the year could result in penalties being assessed. On the other end, if you had a large refund you lost out on having the money in your pocket throughout the year. Changing jobs, getting married or divorced, buying a home or having children can all result in changes in your tax calculations.
The IRS withholding calculator on IRS.gov can help compute the proper tax withholding. The worksheets in Publication 505, Tax Withholding and Estimated Tax can also be used to do the calculation. If the result suggests an adjustment is necessary, you can submit a new W-4, Withholding Allowance Certificate, to your employer.