I prepaid most of my 2018 real estate tax in 2017. How do I enter real estate tax info in my 2018 schedule C for home office information? What about in schedule A?

[zhoux025]

I prepaid most of my 2018 real estate tax in 2017 and has already reported it in 2017 tax return. 

The first question is mainly about  home office used for a resale business. Should I enter the total levies tax for 2018 including what I prepaid in 2017, or should I enter the small remainder that I paid in 2018?

The second question is about schedule A. I think I should just enter the remainder of real estate tax that I paid in 2018, excluding the prepaid amount that I have already reported in 2017 tax return, but the software gives me warning about that. Should I ignore the warning?

Thank you.

[Coleen3]

You can't deduct payments made in 2017 on your 2018 return, no matter the location.