There could be many reasons why this happens. The best thing to do is contact RITA at 800.860.7482, and they will tell you why you are getting bills.
Please note: Penalty and interest are charged on unpaid income tax and unpaid employer withholding tax. The interest rates are set annually by state law. The interest rate applied to each calendar year is the July Federal Short-Term Rate, rounded to the nearest whole percent, plus 5% (Federal short-term rates are found here.)
Here are the interest rates:
|Tax Year||Interest Rate|