My fiance and I both own our home. We received a 1098 in the mail with both of our names on it, but only his SS# under payer identification number. We are filing separately as we are not yet married. Do we both include the 1098 in our tax returns or just

[Fern]

You can only deduct the amount of mortgage interest that you paid.  You can split the interest from the Form 1098 based on how much each of you paid, but both of your deductions cannot be more than the total on the form.  

When entering your mortgage information in Turbo Tax,  you need to indicate that “I co-own this loan and only pay a portion of it” – see screenshots below.