@cdidio33 Thank you for the clarification. See if this helps.
For Mortgage Interest - The mortgage interest on Form 1098 Box 1 should already include the pre-paid interest on your closing statement. Your numbers on your tax return need to match the Form 1098 Box 1 amount. If there is a discrepancy, contact your mortgage lender.
For Property Taxes - The key is not to duplicate your deduction. The seller pays for property tax from Jan 1, 2017, up to the date of sale. The buyer pays for property tax from the date of sale to December 31, 2017. Keep in mind, you cannot deduct delinquent property taxes you pay on the seller's behalf from a prior year. In that case, the property tax paid would be added to the cost of your home.
See this excerpt taken from IRS Publication 17.
Division of real estate taxes between buyers and sellers.
"If you bought or sold real estate during the year, the real estate taxes must be divided between the buyer and the seller. The buyer and the seller must divide the real estate taxes according to the number of days in the real property tax year (the period to which the tax is imposed relates) that each owned the property. The seller is treated as paying the taxes up to, but not including, the date of sale. The buyer is treated as paying the taxes beginning with the date of sale.
You figure your deduction for taxes on each property bought or sold during the real property tax year as follows."
Worksheet 22-1. Figuring Your Real Estate Tax Deduction
1. Enter the total real estate taxes for the real property tax year
2. Enter the number of days in the real property tax year that you owned the property
3. Divide line 2 by 365 (for leap years, divide line 2 by 366)
4. Multiply line 1 by line 3. This is your deduction.
