They include: property tax, mortgage interest, house insurance, house depreciation, utilities and house repairs.
You must apply your Time-Space Percentage to these expenses, but after doing so they still represent thousands of dollars of deductions. (House expenses are claimed on IRS Form 8829 Expenses for Business Use of Your Home.)
If you are married you can claim these deductions as long as either your name or your spouse's name is on the deed.
But, if you are unmarried the answer is different.
If you unmarried you cannot claim certain house expenses unless you have an ownership interest in the home. These expenses are: property tax, mortgage interest, house insurance and house depreciation.
Update: If you married a same sex partner, you can claim these house expenses on your federal tax return after the federal government recognized same sex marriages in 2013.
If you are unmarried you could claim the business portion of utilities and house repairs if you can show that you (not your significant other) paid for them. In the same way you could claim other expenses for your business (food, toys, supplies, etc.) if you can show that you paid for them.
If you are married (including same sex marriages), you can deduct all expenses regardless of which spouse paid for them.
You can claim expenses for the entire year as a married couple as long as you are married as of December 31st of that year. So, it's not too late to go out and get married! Your wallet will thank you.
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