Home office "Deductible Mortage Interest" becomes to "excess mortgage interest" on Schedule C?

mkrmn

This seems like a pretty important bug. I'm trying to switch over from TurboTax but as I enter my home office deduction I'm noticing the numbers are wrong due to a bug in FreeTaxUSA:

I tested this out with dummy values —

First, in the form for home office, I enter:
Deductible mortgage interest: $100
Excess Mortgage interest: $50

Then I go back to "view" my schedule C
Deductible mortgage interest (8829 row 10): EMPTY
Excess Mortgage interest (form 8829 row 16): $150

No matter what I put in the web form, I can't get a value to properly show up in 8829 row 10, unless I put my Mortgage Interest as Casuaty Losses.

This results in very different final calculations, and I only found this when comparing with TurboTax

mkrmn

Ha, looks like this may be a Turbotax bug (though hard to be sure until filing is complete).

According to the instructions for form 8829:

If you claim the standard deduction, you will not include any mortgage interest or real estate taxes on lines 10 and 11; instead, you will claim the entire business use of the home portion of those expenses using lines 16 and 17.