I'm filing my 2023 taxes and encountered some problems. Here's the context: I made a payment of $8000 on pay1040.com on 01/30/2024 for my 2023 return. I made this payment because I had some unexpected gains by the end of 2023, and the taxes were not withheld for that gain. I owed the IRS around $8k in taxes due to that gain. I realized that I can pay estimated taxes on websites like pay1040.com throughout the year. However, the 1040-ES payments have a due date for each quarter, and the deadline for 2023 Q4 is 01/15/2024. So my $8000 payment is not a 1040-ES payment. It is also not a 4868 extension payment. On the website, it just shows as a tax payment for the year 2023.
I did some research on how to report this tax payment on my tax form(link1, link2), and I found the most appropriate way to report this $8000 payment is to put it on 1040 Schedule 3, Line 13z, with the description "tax payment" and the amount of $8000. When I'm trying to report this payment on my TurboTax Desktop Premier, in the EasyStep(default) mode, there is no place for me to input this payment. It only allows me to report 1040-ES payments or 4868 Extension payments, while my $8000 payment does not belong to any of them. So I have to go to Forms mode to manually edit the 1040 Schedule 3 to include my payment. I went to the Form 1040/1040-SR worksheet and clicked on line 31, which directed me to 1040 Schedule 3. Then I tried to add an entry on Line 13z to include my payment. However, it does not respond and does not seem to allow me to input anything. Can you please advise on how I can include my $8000 payment in my return? Thanks!
