Will the federal income tax withheld from your wages be enough to meet your 2015 federal income tax liability? If not, you can choose to make estimated tax payments. However, you should be aware that the penalty rules for underpayment of estimated taxes is applied to each installment – meaning you may owe a penalty when your estimated tax payments (plus withholding) total less than 25% of your required annual payment. Increasing your withholding for the last two months of the year can help you avoid this penalty. Contact us to learn how the estimated tax rules apply to you.