Real estate taxes paid on a vacation home, as long as it is not a rental property are reported on Sch A, along with the real estate taxes of your principal residence.
There is a limitation of $10,000 on Sch A for the taxes section ($5,000 for MFS). If the real estate taxes on the vacation home are included after there is already $10,000 of taxes to deduct, then it will not make a difference and they are not able to be carried over to next year.
Please refer to the following link for additional information:"=
IRS Schedule A and Instructions
