The IRS has advised that pre-paying 2018 state and local real property taxes in 2017 may be deductible only under certain circumstances. It is dependent upon whether the taxpayer makes the payment in 2017 and the real property taxes are assessed prior to 2018. A prepayment of anticipated real property taxes that have not been assessed prior to 2018 are not deductible in 2017.
For additional information, please see the IRS advisory issued on December 27, 2017 at the following link: https://www.irs.gov/newsroom/irs-advisory-prepaid-real-property-taxes-may-be-deductible-in-2017-if-a...
