Late Payment Penalty

• The normal due date for income taxes for any tax year is April 15th of the following year. If you don't send the IRS enough money to cover the taxes you owe by the due date, a late payment penalty may apply, even if you filed your tax return by the due date. The IRS states that the late tax payment penalty is equal to 0.5 percent of the total tax owed for each month that it goes unpaid up to a maximum of 25 percent.
  
  

Late Filing Penalty

• If you do not actually file your tax return by the due date, the IRS may assess a late filing penalty, over and above the late payment penalty, if you owe additional taxes. According to the IRS, the late filing penalty is 5 percent of the tax owed per month up to a maximum of 25 percent. Considering the severity of the late filing penalty, it is important to file your tax return on time, even if you cannot pay your full tax liability by the due date.
  
  

Interest Penalty

• The IRS may charge an interest penalty on taxes owed in addition to late payment and/or filing penalties. The size of the interest penalty depends on current interest rates. The IRS says that the interest charged on unpaid taxes is determined on a quarterly basis and equals the federal short-term rate plus 3 percent. The interest penalties may be small if taxes are only a few months late, but interest can compound if taxes are left unpaid for several years.
  
  

Criminal Charges

• The IRS can bring criminal charges against you for certain illegal tax-related activities. The IRS states that the following are examples of behavior that may merit a criminal prosecution: tax evasion, filing fraudulent tax returns, making false statements and willfully failing to file returns, supply information or pay taxes due.