Sin #1: Deducting the wrong year for property taxes
You take a tax deduction for property taxes in the year you (or the holder of your escrow account) actually paid them. Some taxing authorities work a year behind — that is, you’re not billed for 2013 property taxes until 2014. But that’s irrelevant to the feds.
Enter on your federal forms whatever amount you actually paid in 2013, no matter what the date is on your tax bill. Dave Hampton, CPA, tax manager at the Cincinnati accounting firm of Burke & Schindler, has seen home owners confuse payments for different years and claim the incorrect amount.

Sin #2: Confusing escrow amount for actual taxes paid
If your lender escrows funds to pay your property taxes, don’t just deduct the amount escrowed, says Bob Meighan, CPA and vice president at TurboTax in San Diego. The regular amount you pay into your escrow account each month to cover property taxes is probably a little more or a little less than your property tax bill. Your lender will adjust the amount every year or so to realign the two.

For example, your tax bill might be $1,200, but your lender may have collected $1,100 or $1,300 in escrow over the year. Deduct only $1,200. Your lender will send you an official statement listing the actual taxes paid. Use that. Don’t just add up 12 months of escrow property tax payments.