You will need to access the Schedule 1-A Part IV to see why you did not receive the car loan interest deduction.
To access Schedule 1-A when using the online editions you will have to pay the TurboTax account fees. Or if you are using the Free online edition, it has to be registered in the File section of the program.
To pay the TurboTax online account fees by credit card, without completing the 2025 return at this time, click on Tax Tools on the left side of the online program screen. Then click on Print Center. Then click on Print, save or preview this year's return. On the next page, to pay by credit card, click Pay Now. Complete the credit card section and click on Confirm payment.
