June 5, 2019 Use the Withholding Estimator on IRS.gov to do a Paycheck Checkup to see if you’re having the correct amount of income tax withheld from your pay to avoid tax-time surprises. The estimator gives recommendations to help you adjust your tax withholding. The most common method is increasing or decreasing the number of allowances on Form W-4. Other ways to adjust withholding are: Withhold an extra flat dollar amount per paycheck on their Form W-4. Make estimated tax payments.