Used TurboTax Premier desktop for Mac. I underpaid my 2018 AZ state estimated tax, but TurboTax did not automatically fill in AZ Form 221; consequently I just yesterday learned that I had a penalty due. TT included Form 221 in the list of forms but did not address it in the walk-through and did not consider it an error for the form to have no boxes checked. This error cost me an additional three months of penalty.
The test return I just did filled in the 221 automatically ... so did you accidentally say YES on this screen ? Doing so excludes the penalty from being used NOT that it will be included ... if you don't read the page carefully you may have choose yes instead of no which is what you wanted.
Also the penalty is only an estimate based on your data entries in the program and the state has the right to recalculate the penalty based on the info they have on file and the date the balance due was actually paid.
Thanks for the help with this. I went back to the step-by-step and found the box I had checked wrong. I still wish that error checking had asked me about this, but the lesson learned is that I am being much more careful about my AZ estimated tax this year.