My check was cashed but I received a notice from the state of IL about an estimated Late tax penalty after having paid my taxes. I want to confirm they received everything properly and the notice was a mistake.
An estimated tax penalty has nothing to do with when you filed your tax return or when you paid the tax that was due on the return. Estimated tax is the quarterly payments that you make during the year if your withholding is too low or you have significant income from which no tax is withheld. You incurred an estimated tax penalty because you did not pay enough estimated tax during the year, or did not pay it early enough in the year. Or maybe you didn't make any estimated tax payments at all. The result of the insufficient estimated tax payments was that the amount you owed when you filed your tax return was more than the level at which estimated tax payments are required.
You can check the status of your Illinois estimated tax payments via a "My Tax Illinois" account. See this website for details:
https://tax.illinois.gov/programs/mytax.html
If you got an estmated tax withholding penalty, that tells you the state is looking at your tax return.
Use other superior tax prep software that correctly calculates this penalty based on the dates you paid so you will not be surprised with an additional bill.