Why does TurboTax start my form 1040-X with wrong data ?

[aysoref]

Relevant context:

1 - Using Turbotax Premier Desktop 2025 for Windows. I have the latest update, as of April 4, 2026.

2 - Entered all relevant data and e-filed with IRS. Selected auto withdrawal of the owed taxes from my bank account.

3 - Received email confirmation that IRS accepted the return

4 - Now I am trying to amend this [filed and accepted] return.

5 - Opened the .tax2025 file and went through the initial steps to tell TurboTax that I want to amend this return.

Wrong, unexplained behaviour:

A - The moment I completed step #5 above, and before making any data change, TurboTax told me I have a [small] refund. Should not yet happen at this point !!

B - Chasing the source of that mysterious refund, I see TurboTax created a new form 1040-X [correct behavior] but it auto-populates it with unexpected data. Specifically, using synthetic numbers:

C - say the original, correct AGI is $50,000 as shown on the 1040 form itself.

D - However, the "Original AGI" auto populated in form 1040-X appears as $51,000, and I "paid XXXX" in taxes [this is fiction]. TurboTax also tells me the "correct" AGI is only $50,000 [which is  true] and I should have paid a little less in taxes. Thus I am due a refund !!!

If this is a little confusing, kindly take a couple minutes to read again all the details above - I tried to be as precise, clear and complete as I can.

A few calls to TurboTax support were less than enlightening. My chats included:

- First agent told me I should sign up and pay for tax law expert support, because this is a tax law problem [completely bogus]. She refused to listen to my explaining that we are fighting a software issue, then abruptly told me again she cannot offer tax law advice.

- Next agent took an hour to see my problem on the screen, placing me on hold waiting for some text(s) she had to send to someone else, then waiting a while for some response from an anonymous person then trying to makes sense of that 3rd party reply [who was obviously not in the loop]. No resolution.

- Third agent saw the problem clearly but had to ask for the data file for further analysis by the powers to be, who would determine where this wrong behaviour comes from and whether it is indeed a TurboTax technical issue [I am 99.9999999999% convinced it is].

In summary, PLEASE BEWARE... if you have to amend your filed return, inspect carefully what TurboTax does. Trusting it blindly MAY lead to filing somewhat bogus numbers to IRS = recipe for problems. 

Feel free to share your own experience in this situation. I will try to update this post if / when I receive real answers from TurboTax personnel.

[CatinaT1]

If you opened your return after filing and changed even one small number (perhaps to "see what would happen" or to test a deduction) before clicking the "Amend" button, TurboTax now thinks that "changed" version is your original. When you then start the amendment, it pulls those "in-progress" numbers into Column A.

If you are certain you didn't touch the file before amending, it's possible there were software updates after the time you filed and before you amended. The new calculation (especially for complex credits like the Premium Tax Credit) might retroactively apply to your "Original" column, causing a mismatch with what you actually e-filed months ago.

To fix this, go into Forms Mode, open the 1040X Worksheet, and manually correct the figures in Column A to match your original 'as-filed' return. This ensures the software calculates the 'Change' (Column B) correctly based on the 'Correct Amount' (Column C)."

How to amend my return?

This thread might also be helpful: community thread

[aysoref]

@CatinaT1 Thanks for the reply but it does NOT address the reported problem. Specifically:

* Please, please, please read carefully each and every part of my post. I was very thorough, very complete, very specific, to allow you an easy step-by-step process to reproduce the symptom.

* As I carefully explained, the wrong TurboTax behavior with 1040-X started BEFORE I made any changes to the return itself. This removes a theoretical source of this problem.

* I used THE SAME version of TurboTax to file and THE SAME version to initiate an amendment. There were no software updates in between. This removes another theoretical source of this problem.

* The suggestion to manually correct what TurboTax does is illogical. You know that and I know that. When I pay a decent price for TurboTax, I expect it to be correct and consistent. TurboTax should NOT expect me to manually detect and manually correct its own mistakes - especially when the mistake is so obvious. Kindly review again my - carefully stated - point B, C and D in my post.

In summary, this is an unexplained, wrong TurboTax behavior, It is consistent, i.e. easy to reproduce. As I listed in my post, TurboTax already has the data file and can see the wrong behavior. Still, if you, or someone from your expert product team wants to see it with his/her own eyes, just let me know, I will gladly share the screen  - again - with you and show the obvious issue.