I claimed all of the house mortgage deduction on my filing, but wanted to know how much of that was a part of my refund to give half of that part to the other co-owner?

[VolvoGirl]

You would have to see your refund both ways, one with the mortgage And without it.  Then divide the difference by 2.

[SweetieJean]

Wait...that was incorrect. You can each only claim the amount that you actually paid yourself.

You will have to amend your return, as will the other co-owner.