For 1040X, I now owe $401. I then added $500 to Sch3 extension payment but FEDERAL TAX DUE does not change. Shouldn't it be $99 refund?

[UCcpg]

This is TurboTax online Amend.

[KathrynG3]

Extension payments are not the same as payments with the amended return.

Extension payments are when you have not yet filed. You may want to use Direct Pay or the Electronic Federal Tax Payment System (EFTPS) instead to pay any balance due for an amended return.

For more information, see: 10 Tax Tips for Filing an Amended Return

[UCcpg]

This is not a payment. I didn't enter the extension payment in my original return. In 1040X I added it. But it doesn't reflect towards the total due at the top of the page in TurboTax Online. I tried entering 50,000 and still no change. Does the IRS calculate it? 

[KathrynG3]

The payment must not be reported in the Deductions & Credits tab even after starting the Amended Return. This section is exclusively for tax payments made in 2020, not for 2020.

To pay additional tax due with filing the amendment, tell TurboTax this preference in the Other Tax Situations section under Additional Tax Payments. The first option is Underpayment Penalties and will fill out Form 221 for you. You can select the option for IRS to bill you later or to pay it now. 

The time to record payment details will still not be in this location, but when entering payment information when filing your return. And, the options of Direct Pay and EFTPS would still be valid alternatives to pay more than the exact balance.

Just to review, in order for Form 1040-X to be filled out correctly, the form must begin with the original filing. If changes were made before the amend(change) was begun, then Form 1040-X will change the original and will not document the change.

• If this has occurred, then go back in and delete all changes since filing. Then, follow these steps:
  • From Tax Home, scroll down to Your tax returns & documents.
  • Select Amend(change) my return.
    • For more details, see: How do I amend my 2020 TurboTax Online return?

If you are correcting something because the return was rejected, this does not require amending since the IRS rejected the original filing. In that case, see: How do I fix a rejected return?

@UCcpg

[UCcpg]

No. This is an extension payment made 7/15/2019 for 2019. I am emending my 2019 1040 with 1040X. Among other things, I did not report my extension payment and added Schedule 3 which explicitly has a line for 2019 extension payments made. Before I edit this line, my "due" is 401. After I enter that I paid 500 originally not reported, I am expecting "due" to become "refund" and for it to be 99.

I contacted turbotax support and they said extension payment correction/input may not be supported for 1040X at this time. I see this as a bug though, and would make the filing inaccurate as is. Not sure how this plays with their "accuracy guarantee".