You will be charged the amount you owe plus interest and penalties from the due date of the return. If you filed late you will receive a late filing penalty also.The penalty for filing late is normally 5 percent of the unpaid taxes for each month or part of a month that a tax return is late. That penalty starts accruing the day after the tax filing due date and will not exceed 25 percent of your unpaid taxes.If you do not pay your taxes by the tax deadline, you normally will face a failure-to-pay penalty of u00bd of 1 percent of your unpaid taxes. That penalty applies for each month or part of a month after the due date and starts accruing the day after the tax-filing due date.If you file your return more than 60 days after the due date or extended due date, the minimum penalty is the smaller of $135 or 100 percent of the unpaid tax.If you did not pay 80% pre-payment of taxes, you may also be charged an Estimated Tax Penalty.Interest will be charge at the current rate of interest on money due the IRS.You may go to this website if you have additional questions: Topic 653 IRS Notices and Bills, Penalties, and Interest ChargesHope this is helpful.