Yes - you can deduct interest on a timeshare if it is deeded and recorded in public records and the mortgage is recorded and secured by the financed property.
If you rent out the timeshare during the year, you must also use it as a home for more than 14 days, or more than 10% of the number of days it is rented. You count your days of use and the days of rental only during the time you have a right to use it or to receive any benefits from its rental.
Note:
- Mortgage interest can only be claimed on a maximum of two homes (main home and a second home).
- The deduction is part of your itemized deductions.