What should you do to make sure you don't end up with an unexpected tax bill when filing your tax return? Or maybe you'd rather take home more pay now and get a smaller tax refund later. Or what if your family's income changes during the year? Or you get married, have a child or have other changes in your tax situation? One way to make sure your taxes are right is to use the official IRS Tax Withholding Estimator, available at irs.gov/withholding. The estimator will help you figure out how much tax should be withheld each pay day and will suggest if you should change your withholding. It will ask for information from your most recent pay statements and about any other income you may have. You should also have a copy of your most recent tax return handy. Based on what you enter, it will tell you if you should adjust your withholding and give you instructions on how to do it, including submitting a new Form W-4 to your employer so they can withhold the correct amount of taxes from your pay. Many employers provide an electronic method to update your W-4. Or you can download a Form W-4 from the estimator results page or from irs.gov/w-4 The earlier you change your withholding, the more time there is for tax withholding to take place evenly during the rest of the year. Waiting means there are fewer pay periods to make the tax changes, which could have a bigger impact on each paycheck. So get started at irs.gov/withholding.