@susie1162 --
"Equitable ownership" is not the issue here. Since your name is on the title/deed, you have an actual ownership interest. So you qualify in that regard.
But in order for you to deduct the mortgage interest, the mortage must be a secured debt on a qualified home in which you have an ownership interest. A "qualified home" means your main home or your second home. See Qualified Home in this IRS reference for details:
https://www.irs.gov/publications/p936#en_US_2021_publink1000229900
So, with regard to your deducting mortgage interest, the issue is whether or not the home is a qualified home for you.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
