It won't let me take a deduction on a car I purchased because it was calculated using the wrong rate "undefined"

Forum|Forum|3 months ago
April 16, 2026
1 reply
271 views

I'm trying to deduct a car purchase. When I enter the car price and sales tax, it gives me a message saying I can't take the deduction because the amount is different from the general rate. But the general rate it shows is "undefined". I've used the IRS tax calculator for large purchases. (https://apps.irs.gov/app/stdc) I live in Seattle, WA, and the IRS site says the state rate is 6.5% and the local rate is 3.85% for a total of 10.35%. But when I enter the taxes I paid, which add up to 10.35%, whether or not I check the box that says "The sales tax rate for this purchase was different from undefined%", it won't let me take my deduction.

Best answer by MarilynG

Did you add your State and tax rate in the previous screens? That may account for the 'undefined'. If you paid more in State Taxes, that's the deduction you'll get, instead of the Sales Tax deduction; you can't have both. You'll see it on the Tax and Interest Worksheet.

@user17763467014

DaveF1006

Level 15

Try entering this in this manner to see if this works better.

Navigate to Federal > Deductions & Credits.
Find Estimates and Other Taxes Paid and select Sales Tax.
Choose Easy Guide when asked how you want to calculate your deduction.
The Fix: When you get to the screen for Major Purchases, enter the Item Type, Description, and Cost.
Leave the "Sales Tax Percent" field blank. 6. Only fill in the Sales Tax Paid amount (the actual dollar amount from your car's purchase order).

Note: TurboTax support specifically recommends leaving the percentage blank if the software is throwing an error, as it will use the dollar amount you provided to calculate the deduction instead of trying to validate the rate.

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user17763467014Author

Level 2

That didn't work. Here's what I tried:

* I entered just the cost, but not the tax paid - It wouldn't let me hit next, saying that I need to enter more information.
* I entered just the tax paid, but not the cost - It let me hit next, but on the next screen it gave me the same error about not being able to take a deduction "because it was calculated using a rate that does not match the general rate for your location (undefined)." (Even though Turbotax calculated it itself.)
* I entered both the cost and the tax - It let me hit next, but on the next screen it gave me the same error about not being able to take a deduction "because it was calculated using a rate that does not match the general rate for your location (undefined)."

In all cases, I left "The sales tax rate for this purchase was different from undefined%" unchecked.