since you are a legal owner of the real estate the IRS allows a deduction for the mortgage interest even though you are not directly liable for the debt. however, there are rules. Mortgage payments and taxes paid from a joint account with two equal owners are presumed to be paid equally by each account owner (absence evidence to the contrary). However, if payments are made from separate funds, each taxpayer is entitled to deduct all the interest and taxes they pay with their separate funds (CCA 201451027).
