- The limitations for deducting home mortgage interest apply whether you are deducting mortgage interest on just your primary home or also on a second home. As of 2011, you can only deduct the interest on the first $1 million of mortgage debt, $500,000 of married filing separately; and the first $100,000 of home equity debt, $50,000 if married filing separately.
For example, if you are single and have a primary mortgage of $700,000, you can only deduct the first $400,000 on your second-home mortgage. Conversely, if your home mortgage is $150,000 and your second-home mortgage is $100,000, you can deduct all the interest. - If you do not rent out your second home at all, you can claim the interest as part of your mortgage interest deduction. If you do rent out your home, you must use your home for your own purposes for at least 14 days per year, or 10 percent of the time you rent it out, whichever is greater. For example, if you rent out the home for a week, you must use it for 14 days. If you rent it out for 200 days, you must use it for at least 20 days.
- You can only deduct the interest on one second home at a time, even if you have multiple residences you use throughout the year. The IRS also limits when you can change which home you use as your second home for the purposes of the mortgage interest deduction. You can replace a previous second home with a house you just bought at the time of purchase; you can change your main home to your second home if it no longer qualifies as your main home; or you can select a new second home when the home you currently use as your second home is sold or becomes your main home.
- To claim mortgage interest on your second home, you must itemize your tax deductions. To itemize, file with Form 1040 and Schedule A. On line 10 of Schedule A, enter the amount of deductible second-home mortgage interest plus any deductible mortgage interest from your main home. This deduction, combined with any other itemized deductions you claim, reduces your taxable income for the year. When you submit your tax return, be sure to include Schedule A and the Form 1098 that your lender sends you showing how much mortgage interest you paid during the year.