April 10, 2018 After recent tax law changes, consider a paycheck checkup using the IRS’s Withholding Estimator. This can help prevent an unexpected tax bill in 2019. A paycheck checkup is especially important if you: Are a two-income family. Have two or more jobs at the same time or only work part of the year. Claim credits like the child tax credit. Have dependents age 17 or older. Itemized deductions in 2017. Have high income or a complex tax return. Have a large tax refund or tax bill for 2017. See IRS.gov/taxreform for more information.