You the IRS reserves the right and ability to assess penalties and a multitude of penalties to any tax liability. These may range from penalties for failure to file or failure to file on time. That means if you just didn't file your tax returns or you missed the April 15th or the extension October 15th deadline, there are also penalties for failure to make estimated tax payments and failure penalties for under withholding. There are a multitude of penalties that the IRS can assign for these unpaid or underpaid types of taxes owed. In addition to that, those types of penalties typically are based on certain factors like: is it for multiple years or how old the liability is, as well as if it is recurring. So, if you incur taxes for a specific reason for under withholding, let's say year in and year out, then they may assign additional penalties. Now, these penalties are capped at 25 percent. However, there is no direct or flat number for these penalties if they are to be assigned. Sometimes we see that they assign multiple types of penalties, and in a similar situation, they may only assign one type of penalty. So, it really does come down to the type of situation you are in, how much you owe, and the reasons why you owe. Those are more determining factors in the amount of penalties that may be assigned.