Problem with underpayment penalty calculation for Montana

Forum|Forum|5 months ago
March 15, 2026
6 replies
172 views

When I filled my taxes in Turbotax for the state of Montana (for 2025), it calculated an underpayment penalty of $7. I believe this is a problem with the software. I entered the dates I made the actual payments (4/15/2025, 6/15/2025, 9/15/2025, and 1/23/2025). It then asked me when I would be paying the underpayment (of $85) as well as the $7 penalty calculated and I put the date of 3/14/2026 as I WAS going to pay when I filed. When I finally found and reviewed the calculation today, it showed that each of my estimated payments were made on 3/14/2026 even though I actually made the payments as stated above. Does anyone know who I can talk to at Turbotax about this? I don't want to amend my taxes for $7, but they need to know there is a problem with the software. I spoke with someone in the help center and with an "expert" but neither knows how the calculation is made and couldn't help.

TurboTax Free Edition Online

MelindaS1

Level 6

I'll take a look at it, if you share your diagnostic file. Please tag @MelindaS1 in your response. Instructions:

You can provide a diagnostic copy of your tax data file so that someone here can take a closer look. The diagnostic file will not contain personally identifiable information, only numbers related to your tax forms.

If you would like to provide us with the diagnostic file, follow the instructions below and post the token number along with which version of TurboTax you are using and what states you are filing in a follow-up thread. It would be helpful to have a screenshot of the token number to prevent it from being redacted.

Use these steps if you are using TurboTax Online:

Sign in to your account and be sure you are in your tax return.
Select Tax Tools in the menu to the left.
Select Tools.
Select Share my file with agent.
A pop-up message will appear, select OK to send the sanitized diagnostic copy to us.
Post the token number here.

If you are using a CD/downloaded version of TurboTax, use these steps:

Select Online at the top of the screen.
Select Send Tax File to Agent.
Click OK.
Post the token number here.

**Say "Thanks" by clicking the thumb icon in a post. **Mark the post that answers your question by clicking on "Mark as Best Answer"

CrazyleafAuthor

Level 2

I'm not sure if I did it right, but I shared the diagnostic version. I dont know if it tagged you or not. The token number is 1341943. I was using the online free version. Please let me know if you need anything else. @MelindaS1

MelindaS1

Level 6

Thanks for the token. It looks weird with how it prints, but the good thing is it's not calculating wrong. If you look at how the form works, it asks for the date you paid the amount on Line 10 (underpayment), but the only quarter in which you have an underpayment amount on Line 10 is Q4. That's why only Q4 is calculating an underpayment penalty on Line 14. So you have nothing to worry about. Those dates are not included in the calculation for the other quarters, and there's no penalty being applied to the other quarters at all. See below: