The loan interest is considered "mortgage interest" even though you have no 1098. If you have a percentage of the ownership, the timeshare is considered a second home. On Schedule A this will go on Line 11 Home mortgage interest not reported to you on Form 1098. A second home is a residence that you intend to occupy in addition to a primary residence for part of the year. ... Often, to qualify for a second-home loan, the property must be located in a resort or vacation area (such as the mountains or near the ocean) or a certain distance from the borrower's primary residence.You can deduct home mortgage interest if the mortgage is a secured debt on a "qualified home" in which you have an ownership interest.
Here are the steps:
1) Select Federal Taxes from the top menu
2) Select Deductions/Credits (just below Federal Taxes)
3) Click the Edit/Add button next to Mortgage Interest, Refinancing, and Insurance
4) Select Add a Lender (you should be able to find the lender name or use name from the annual summary) and answer the interview questions. Keep your records.
