Home loans

Hi, my situation is similar but both my Mom and I are on the 1098 but my Mom's name comes first.  I am paying the mortgage which includes the taxes and insurance through the escrow account.  My Mom is paying her HOA fees.  I sent my taxes to a tax accountant referred by a friend and he said that because my Mom's name comes first on the 1098, that I can't claim anything to do with the purchase of the condo or the resulting 1098 because my name is second on the form.  If the above answer is correct, then I should be able to deduct the interest, taxes, and insurance, right?  Any assistance would be appreciated and if you know of any formal documentation that I can give the tax accountant to validate my claim, that would be awesome.  Thank you in advance.