You simply add these amounts to the other property taxes you may have paid for 2017 to come up with one total number. If your 2017 property taxes were reported on Form 1098, then you should enter the 2017 amounts with your mortgage interest in the Form 1098 section and then use the other property tax payments section to enter the 2018 amounts.
- If using online: Log into your account and click Take Me to My Return (you must click this first)
- Use the search function (magnifying glass in the top right-hand corner for online or "search topics function for Mac destop or search bar for Windows desktop) to search for "property taxes" and click the "jump to property taxes" link
- Follow the screens to enter your property taxes
You can also find this section under Federal taxes -> Deductions and Credits -> Click full list or show all -> Your Home -> Property Taxes
Note: It doesn't really matter where you enter the property taxes (TurboTax includes two sections - one section in the Form 1098 Mortgage interest section and one separate spot for those that don't receive Form 1098 or have additional property taxes called Property Taxes that you could enter these amounts). The key is to make sure you don't enter them twice.
Please make sure you keep documentation that your property taxes were assessed and paid in 2017. In order to be deductible, your 2018 property taxes must have been actually assessed and paid in 2017.