How should my boyfriend and I claim our mortgage?

This answer was provided by Mark Misselbeck, Levine Katz Nannis & Solomon PC, Needham.

Q: My boyfriend and I own a house together. How do we decide who should claim the mortgage interest and real estate taxes to get the most benefit? - Ruby, Belchertown

A: Deductions for a property that is owned together with another person who is not your spouse depend on ownership interest and actual payment.

If you each own one half of the property, you are each responsible for one half of the mortgage interest and real estate taxes (presuming you each put up one half of the down payment and closing costs for the property). Usually, only the owner may claim the deductions for the property. If one owner has paid expenses for the other owner, either they have made a loan to that other owner to pay their expenses or, if the first owner's interest in the property is in jeopardy of forfeiture due to non-payment of items with respect to the property by the other owner, that owner may deduct the expenses they have paid. The paying owner should either receive an increased ownership interest in the property or they have a claim against the non-paying owner which, if recovered, would have to be reported as income, to the extent that they took a tax deduction for the payments that they made that actually resulted in a tax deduction that reduced their tax liability.

You may not choose to take a disproportionate amount of the deductions, in relation to your ownership interest, merely because you will get a greater tax benefit than the owner who is entitled to the deduction.